Plumbers in London

Plumbers in London

Replacing taps

Changing the old taps on your basin is a bright and practical way of making your bathroom more attractive. It may also be a good idea if they are old and inefficient.

There may be a number of reasons why you wish to replace the taps supplying your sink, basin or bath. They may continually drip or leak, where new taps would give efficient, trouble-free service. Perhaps you want the advantages that mixers have over individual taps or perhaps it is simply that the chromium plating has worn off leaving the taps looking incurably shabby. It is more likely, however, that appearance, rather than malfunction, will be your reason for changing. There are fashions in plumbing fittings as in clothing and furniture. Taps of the 1950s or 60s are instantly recognisable as out-of-date in a bathroom or kitchen of the 1980s. Fortunately, fashions in sinks, basins and baths have changed rather less dramatically over the past three decades. There is probably no more cost-effective way of improving bathroom and kitchen appearance than by the provision of sparkling new taps or mixers.

Choosing taps

When you come to select your new taps you may feel that you are faced with a bewildering choice. Tap size, appearance, the material of which the tap is made, whether to choose individual taps or mixers and – for the bath – whether to provide for an over-bath shower by fitting a bath/shower mixer: all these things need to be considered. Size is easily enough dealt with. Old taps and mixers might be in imperial sizes.

There are, however, most suppliers designate taps by the metric size, not of the taps themselves, but of the copper supply pipes to which they will probably be connected. Such a supplier might refer to bath taps as 22mm and sink and basin taps as 15mm. Most taps are made of chromium-plated brass, though there are also ranges of enamelled and even gold-plated taps and mixers. Although taps and mixers are still manufactured with conventional crutch or capstan handles, most people nowadays prefer to choose taps with ‘shrouded’ heads made of acrylic or other plastic. In effect, these combine the functions of handle and easy-clean cover, completely concealing the tap’s headgear. A still popular alternative is the functional .

‘Supatap’, nowadays provided with plastic rather than metal ‘ears’ for quick and comfortable turning on and off. There is also a very competitively priced range of all-plastic taps. These usually give satisfactory enough service in t he home, but they cannot be regarded as being as sturdy as conventional metal taps, and they can be damaged by very hot water. So far as design is concerned the big difference is between ‘bib taps’ and ‘pillar taps’. Bib taps have a horizontal inlet and are usually wall-mounted while pillar taps have a vertical inlet and are mounted on the bath, basin or sink they serve.

Taking out old basin taps

When replacing old taps with new ones the most difficult part of the job is likely to be – as with so many plumbing operations – removing the old fittings. Let’s first consider wash basin taps. You must, of course, cut off the hot and cold water supplies to the basin. The best way of doing this will usually be to tie up the float arm of the ball valve supplying the cold water storage cistern so as to prevent water flowing in. Then run the bathroom cold taps until water ceases to flow. Only then open up the hot taps. This will conserve most of the expensively heated water in the hot water storage cylinder. If you look under the basin you will find that the tails of the taps are connected to the water supply pipes with small, fairly accessible nuts, and that a larger – often inaccessible – back-nut secures the tap to the basin.

The nuts of the swivel tap connectors joining the pipes to the taps are usually easily undone with a wrench or spanner of the appropriate size. The backnuts can be extremely difficult – even for professional plumbers! There are special wrenches and basin or ‘crows foot’ spanners that may help, but they won’t perform miracles and ceramic basins can be very easily damaged by heavy handedness. The best course of action is to disconnect the swivel tap connectors and to disconnect the trap from the waste outlet. These are secured by nuts and. are easily undone. Then lift the basin off its brackets or hanger and place it upside down on the floor.

Apply some penetrating oil to the tap tails and, after allowing a few minutes for it to soak in, tackle the nuts with your wrench or crowsfoot. spanner. You’ll find they are much more accessible. Hold the tap while you do this to stop it swivelling and damaging the basin. Fitting the new taps When fitting the new taps or mixer, unscrew the back-nuts, press some plumber’s putty round the tail directly below the tap body or fit a plastic washer onto the top tail.

Push the tails through the holes in the basin. Slip flat plastic washers over the tails where they protrude from beneath the basin, screw on the back-nuts and tighten them up. Make sure that the taps or mixer are secure, but don’t overtighten them. To make tightening • easier, (and undoing, if ever necessary) use top-hat washers. All that remains to be done is to connect the swivel tap connectors to the tails of the new taps or mixer. You will see that a tap connector consists of a lining – with a flange – that is inserted into the tap tail and is then secured by the coupling nut.

This nut is provided with a washer to ensure a watertight connection. When renewing taps you may well need to renew this small washer. It is possible that when you come to connect the water supply pipes to the taps you will get an unpleasant surprise. The tails of modern taps are slightly shorter than those of older ones and the tap connectors may not reach. If the water supply pipes are of lead or of copper it is quite likely that they will have enough ‘give’ to enable you to make the connection but, if not, there are extension pieces specially made to bridge the gap.

Bib taps

If you’re replacing existing bib taps with those of a more modern design, it’s a relatively simple matter of disconnecting and unscrewing the old ones and fitting the new taps in their place. However, it’s quite possible that you’ll want to remove the bib taps altogether and fit a new sink with some pillar taps. This will involve a little more plumbing work. To start with, turn off the water supply and remove the taps and old sink. If the pipework comes up from the floor, you’ll need to uncover the run in the wall to below where the new sink will go. You should then be able to ease the pipes away from the wall and cut off the exposed sections.

This will allow you to join short lengths of new pipe, bent slightly if necessary, to link the pipe ends and the tap tails. Alternatively, if the pipes come down the wall you’ll have to extend the run to below the level of the new sink and use elbow fittings to link the pipe to the tap tails. In either case it’s a good idea to fit the taps to the new sink first and to make up the pipework runs slightly overlong, so that when the new sink is offered up to the wall you can measure up accurately and avoid the risk of cutting off too much pipe. Rather than having to make difficult bends you can use lengths of corrugated copper pipe. One end of the pipe is plain so that it can be fitted to the 15mm supply pipes with either a soldered capillary or compression fitting; the other end has a swivel tap connector.

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Positioning a washing machine or dishwasher

Water

Place the washing machine and the dishwasher as close to the existing water supply as possible. The water can be supplied hot or cold, depending on the appliance and the general water system in your home. If the water arrives hot you save time, especially with an automatic machine which empties after every cycle.

On the other hand, extracting water from your household system will rob your central heating or bathroom of hot water. Appliance manufacturers usually state whether hot or cold water should be used. To obtain water from your main supply, form a junction at a convenient height in the existing pipe. The plumbers should insert a stop-tap in the extension pipe so that the machine can be moved without having to cut off the water supply to the whole house.

Appliances are fitted with a flexible hose for easy connecting and tolerance when finally positioning the machine. You should try to conceal pipes from general view wherever possible. Machines should be filled at the water pressure recommended by the manufacturers.
Consult your water board for local pressures, and they will advise you on the kind of regulating valve you will need, if any, A water softener may also be needed in some areas.

Waste outlets

In Britain the Building Regulations impose certain restrictions on waste and drain pipes. Drains must have a sufficient slope to enable the water to run away quickly.

Changes in the direction of a drain have to be fitted with an inspection chamber, and connections to existing drains are best made at such points.

Waste pipes in houses built in Britain since 1966, sometimes have to be inside, and this also applies to additional pipes. Additions to houses built before 1966 , on occasions, can be fixed outside along with the original pipes. Each waste pipe requires an ‘S’ bend water sealed trap to prevent drain odours from reaching the appliances. However, pipes from different sources (e.g. a sink and washing machine) can meet inside the building so that you only have to penetrate the wall in one place.

Positioning a laundry

You may be limited in your choice of position for a laundry. If none of your rooms is suitable for conversion, consider building an extension.

The position of a conversion or extension should be influenced strongly by the existing plumbing in your house. Laundries need hot and cold running water and a waste outlet. Position the laundry as close as possible to the existing water supply and drains, as this will enable a simple connection to be made to the water supply. It will also reduce, or eliminate, the need for the installation of new drains (underground), which can be very expensive.

Ideally the waste pipe (above ground) from your laundry appliances should issue directly into the existing gully (sink at ground level leading to the drain). You may consider that other factors take priority over the cost of extending a drainage system. Access, for instance, is one which is very important and is influenced by the size of your wash and when you do it. A large family, living in a house, will probably want easy access from the kitchen and to the garden. A young family with no children, who are out at work all day, and live in a flat, may find a room off an upper floor bathroom quite adequate for a laundry.

Additional requirements

A well-equipped laundry should have a deep sink for some soaking prior to machine washing, and for hand washing. Provide hanging rails over the sink for drip-dry clothes, and also a draining board if the sink is not large enough to catch all the drips. A working surface approximately 1.83m x 610mm (6 ft x 2 ft) is necessary for sorting, folding and temporary stacking of clothes. The top should be strong enough to take an ironing machine if required, and should be 864mm (2ft lOin) high for ironing in a standing position.

A retractable lower board can be incorporated for seated ironing. Storage should include a cupboard out of children’s reach for bleaches, dyes, detergents, washing powders etc. A tall cupboard is also required if you use a portable ironing board. This should be fitted with an fireproof material, ventilated compartment for immediate storage of a hot iron. Provision of storage for dirty clothes, clean linen and an airing cupboard will depend on the layout of the rest of your home. If you are generally short of such space, large cupboards in the laundry could be very useful.

Insulating hot water tanks

Insulating hot water tanks

Although you could in theory lag your hot water tank by adapting any of the methods that are used for cold water tanks, in practice you will nearly always find that you have no choice but to use a proprietary jacket. The fact that most hot water tanks are situated in airing cupboards means that blanket insulation is out of the question, and unless your tank is a rectangular one (which these days are very rare) you won’t be able to use polystyrene.

Proprietary jackets for hot water tanks are made of the same materials as those used on cold water tanks and are just as easy to fit. The system used to fasten the jacket to the tank varies, but basically at the top you secure the ‘envelopes’ round the hot water supply pipe with a loop of cord, while further down you hold them in place with straps. The base of the tank is left uninsulated, as is the capping and wiring of any immersion heater.

Insulating water tanks and pipework

Insulating water tanks and pipework

Lagging water tanks and pipes and insulating behind radiators reduces the amount of heat that escapes, so you spend less money heating water up, and hot water stays hotter for longer.

Insulation is important because it reduces I heat loss, and when properly applied to your water system it benefits you in a number of ways. Firstly, it saves you money by slowing down the rate at which heat is lost from the pipes and tanks of your hot water system. Secondly, by reducing the heat loss from your cold water system (and even the coldest water contains some heat) it tends to keep your cold water warmer in winter, thereby minimising the risk of frozen pipes. Warmer cold water in winter also means that it takes less energy to heat it up to the desired temperature when it enters your hot water tank. In this respect too insulation saves you money. So for all the above reasons you should consider properly insulating your pipes and tanks. The cost of the materials you will need is small and the potential savings great.

And if you have already insulated your loft floor then this is one job you really must attend to. It has to be done because the temperature of your loft in winter will now be only marginally higher than that of the air outside, which means that the danger of any exposed pipework freezing in cold weather is greatly increased. Ideally you should therefore insulate your pipes and tanks before you tackle the loft floor. And don’t forget that the risk of frozen pipes also applies to pipes in the cellar, and anywhere else where they might be subject to extremes of cold Before purchasing the insulation material for your pipes and tanks, work out how much you are likely to need. Most tanks will have their capacity and/or their dimensions marked on them somewhere – if yours don’t then measure them yourself.

You will also need to calculate the combined length of the pipes you intend insulating and establish what their diameter is – though this last measurement is only important if you plan to use split sleeve insulation. As you’ll want the insulation on your tanks to overlap that which you fit to any pipes that run into them, it’s best to start by insulating your pipework.

Insulating pipes

Two types of pipe insulation are commonly available. The first is made out of a glass fibre or mineral wool material similar to that used for insulating loft floors, but supplied in bandage form (75 to 100mm’3 to 4m wide and 10mm/%in thick) generally with a flimsy plastic backing. The second type comes in the form of split sleeves which are made from some sort of foamed material – usually plastic. Both types of pipe insulation have their advantages and disadvantages and both types are cheap. And since there is no reason why they can’t be used side by side on the same pipe system, you’ll almost certainly find that the easiest way to insulate your pipework is by using lengths of both.

Fitting the sleeves is very straightforward. You simply prise apart the slit that runs along the length of the sleeve and slip the insulation over the pipe. It’s advisable to tape the sleeve at intervals, and you must do so at joins. At bends, where the sleeves will tend to come apart, you should tape the split lengthways. Once sleeve insulation has been fitted, it can easily be slid along a length of pipe to protect a part of it that may be hard to get at. However, you should bear in mind that it won’t be able to get beyond any pipe clips, very sharp bends or bulky joints it may encounter.

You’ll find that most flexible sleeves will readily slide round curves and even 90° bends made using soldered fittings, but whenever you run up against problems in the form of bulky compression elbows or tee connectors the sleeves will have to be cut accordingly. However, in some circumstances you might well find that bandage insulation provides the better solution. To fit round a 90° elbow the sleeve should be cut in two and the sleeve ends then cut at an angle of 45° before being slipped over the pipe. You should then tape over the resulting join.

Insulating cold water storage tanks

When it comes to insulating your cold water storage tank and central heating expansion tank (if you have one), there are a number of options open to you. If your tank is circular you could cover it with a proprietary jacket consisting of a number of polythene or plastic ‘envelopes’ filled with insulant; or you could simply wrap it up in a layer of mineral wool or glass fibre blanket similar to – or even the same as – that which is used to insulate loft floors. If, on the other hand, your cold water tank happens to be rectangular then you could construct a ‘box’ for it yourself out of expanded polystyrene, or buy a proprietary one ready-made.

A proprietary jacket couldn’t be easier to fit: you simply pull it into position and then tie it in place – tapes are sometimes provided by the manufacturer. If you have to cut into the jacket to accommodate a pipe, make sure that you sea! it up again with plastic adhesive tape to prevent moisture getting in and the insulating material from escaping. Expanded polystyrene kits are also extremely easy to fit. Apart from having to fix the pieces of polystyrene together with tape, string or polystyrene cement, the only work you will have to do is to make cut-outs for the pipework. More work will be required should you decide to make your tank kit out of sheet polystyrene.

CLEARING BLOCKAGES

CLEARING BLOCKAGES

There are few plumbing emergencies quite as unpleasant as a blocked drain or waste pipe. However, it’s usually possible to cure the problem if you know what to do when you’ve tracked down the blockage and you have the right equipment.

Professional plumbers rarely relish being called out to deal with a blockage. There are specialist drain clearance firms, but they can’t always be contacted quickly in an emergency – and their charges reflect what can sometimes be the unpleasantness of the job. Drain or waste-pipe clearance is usually well within the capacity of the householder, and there are certainly few more cost-effective do-it-yourself jobs about the house.

drains

Coping with blocked sinks

The outlet of the sink, usually the trap immediately beneath the sink itself, is the commonest site of waste-pipe blockage. Usually the obstruction can be cleared quickly and easily by means of a sink-waste plunger or force cup. This is a very simple plumbing tool obtainable from any do-it-yourself shop, ironmongers or household store. It consists of a rubber or plastic hemisphere, usually mounted on a wooden or plastic handle. Every household should have one.

To use it to clear a sink waste blockage, first press a damp cloth firmly into the overflow outlet, holding it securely with one hand. Then pull out the plug and lower the plunger into the flooded sink so that the cup is positioned over the waste outlet. Plunge it up and down sharply half a dozen or more times. Since water cannot be compressed, the water in the waste between the cup and the obstruction is converted into a ram to clear the blockage.

The overflow outlet is sealed to prevent the force being dissipated up the overflow. If your first efforts at plunging are unsuccessful, persevere. Each thrust may be moving the obstruction a little further along the waste pipe until it is discharged into the drain gully or the main soil and waste stack. Should plunging prove unsuccessful you’ll have to gain access to the trap. Brass and lead U-shaped traps have a screwed-in plug at the base. With plastic U-shaped and bottle traps the lower part can be unscrewed and removed – see Ready Reference. Before attempting this, put the plug in the sink and place a bucket under the trap; it will probably be full of water unless the blockage is immediately below the sink outlet, and the chances are that opening the trap will release it. Having done so, probe into the trap, and into the waste pipe itself.

You can buy purpose-made sink waste augers for this purpose, but you’ll find that a piece of expanding curtain wire, with a hook on the end, can be equally effective.

Blocked baths and basins

Basin and bath wastes are less likely to be totally blocked than sink wastes but, when blockages do occur, they can usually be cleared in the same way. They are, however, very subject to partial blockage. The waste water is often found to run from the bath or basin ever more slowly. This may be due to a build-up of scum, scale and hair on the inside of the waste pipe, and the use of a proprietary drain-clearing chemical will usually clear it.

These frequently have a caustic soda base, so they should be kept away from children and handled with care, strictly in accordance with the manufacturer’s instructions. Before spooning them into the bath or basin waste outlet it is wise to smear petroleum jelly over the rim of the outlet to protect the chromium finish, especially with plastic baths or fittings. Partial blockage of a wash basin waste may often be caused by hair suspended from the grid of the outlet. This may be all but invisible from above, but probing with a piece of wire (the old standby of a straightened- out wire cotahanger is useful) can often produce festoons.

If you can’t clear the hair by this means, unscrew the nut that connects the threaded waste outlet to the trap and pull the trap to one side. Now use a pair of pliers to pull the hair away from beneath the grid.

Overflows from gullies

Where waste pipes and downpipes discharge into gullies, the first signs of trouble may be when the gully overflows and the surrounding area is flooded as a result. The gully trap has probably become blocked, either by blown leaves or other debris, or by a build-up of grease and scum on the sides of the trap. Raise the gully grid if one is fitted (and get a new one if it’s broken or missing). Then scoop out any debris with a rubber-gloved hand or an improvised scoop, scrub the gully out with caustic soda and flush it through with plenty of clean water before replacing the grid.

Blockages below ground

A blockage in the underground drains may be shown up by a WC which, when flushed, fills with water almost to the rim and then very slowly subsides, or by dirty water seeping from under a manhole cover. You’ll need a set of drain rods to clear any underground blockage. It is best to hire these from a local tool hire firm if and when the emergency arises.
A drain that blocks sufficiently frequently to justify the purchase of a set of rods undoubtedly has a major defect that needs professional advice and attention. Raising the manhole covers will give you an indication of the position of the blockage. If, for instance, the manhole near your front boundary is empty, but the one beside the house into which the soil pipe and yard gully discharges is flooded, then the blockage must be between these two manholes. Screw two or three lengths of drain-rod together, add the appropriate accessory to one end and then lower it into the flooded manhole. Feel for the drain half-channel at its base and push the rod end along it and into the drain towards the obstruction.

Screw on extra rods as necessary until you reach and clear the blockage. You may find it easier to push the rods into the drain – and to extract them again – if you twist them as you do so. Always twist in a clockwise direction.

If you twist anti-clockwise the rods will unscrew and one or more lengths will be left irretrievably in the drain. Many older houses have intercepting traps. These traps, which were intended to keep sewer gases out of the house drains, are the commonest site of drain blockage. You can see if your drains have an intercepting trap by raising the cover of the manhole nearest to your property boundary before trouble occurs and looking inside. If there is an intercepting trap the half-channel of the gully will fall into what appears to be a hole at the end of the manhole; actually it is the inlet to the trap. Immediately above this hole will be a stoneware stopper. This closes the rodding arm giving access to the length of drain between the intercepting trap and the sewer.

A blockage in the intercepting trap is indicated when all the drain inspection chambers are flooded. It can usually be cleared quite easily by plunging. To do this, screw a drain plunger (a 4in or 100mm diameter rubber disc) onto the end of a drain rod. Screw on one or two other rods as necessary and lower the plunger into the flooded manhole. Feel for the half-channel at its base and move the plunger along until you reach the inlet of the intercepting trap. Plunge down sharply three or four times and, unless you are very unlucky, there will be a gurgle and the water level in the manhole will quickly fall.

Very occasionally, there may be a blockage between the intercepting trap and the sewer, and the point must be made that this length of drain is the householder’s responsibility, even though much of it may lie under the public highway. To clear such a blockage the stoneware cap must be knocked out of the inlet to the rodding arm (this can be done with the drain rods but it isn’t the easiest of jobs) and the rods passed down the rodding arm towards the sewer. Intercepting traps are also subject to a kind of partial blockage that may go unnoticed for weeks or even months. An increase in pressure on the sewer side of the trap – due to a surge of storm water, for instance – may push the stopper out of the rodding arm.

It will fall into the trap below and cause an almost immediate stoppage. However this will not be noticed because sewage will now be able to escape down the open rodding arm to the sewer. The householder usually becomes aware of a partial blockage of this kind as a result of an unpleasant smell, caused by the decomposition of the sewage in the base of the manhole. The remedy is, of course, to remove the stopper and to replace it. Where the trouble recurs it is best to discard the stopper and to lightly cement a glass or slate disc in its place. In the very unusual event of a stoppage between the intercepting trap and the sewer, this disc can be broken with a crowbar and replaced after the drain has been cleared. After any drain clearance the manhole walls should be washed down with a hot soda solution and a garden hose should be used to flush the drain through thoroughly.

High and low pressure water supply

High and low pressure water supply

The water pressure under which a ball-valve operates is an important factor, as the size of the hole in the nozzle of the valve will be either smaller or larger according to whether it is under high pressure (ie, mains pressure) or low pressure (ie, supplied by water from a storage tank). Older Portsmouth valves have either HP (high pressure) or LP (low pressure) stamped on their bodies, and will only operate satisfactorily under the pressure for which they are designed. Modern valves, on the other hand, have interchangeable nozzles which allow you to convert them from low to high pressure or vice versa.

If the plumbers fits a high pressure valve (or nozzle) in a situation where a low-pressure one is required this will result in an agonisingly slow re-fill. A constantly dripping overflow may be the sign of a low pressure valve that has been fitted to a cistern that is fed by the mains. In some areas, mains pressure varies considerably throughout a 24-hour period. During the day, when demand is high, pressure will be low, whereas in the evening as demand falls off the pressure increases. These fluctuations in pressure don’t affect low pressure valves but they do affect high pressure ones, which can perform erratically as a result. You can overcome this problem if it affects you by replacing your high pressure ball-valves with equilibrium valves.

Equilibrium ball-valves
The plumber can use Portsmouth and diaphragm equilibrium valves. These are both designed to allow a small quantity of water to pass through or round the washered piston (or diaphragm) into a watertight chamber beyond. Acting as it does on the rear of the piston, and being at the same pressure as the mains, the water in the chamber ensures that the piston is held in equilibrium. What this means in practice is that the valve is operated solely by the movement of the float arm, rather than by a combination of the movement of the float arm and the pressure of the incoming water as is the case in an ordinary high-pressure valve. In addition to re-filling your cistern promptly regardless of any fluctuations in mains pressure, equilibrium valves also eliminate the ‘bounce’ as the valve closes – a common cause of water hammer. A diaphragm equilibrium valve will give you a particularly rapid and silent refill.

Stop-valves, gate-valves and ball-valves

Stop-valves, gate-valves and ball-valves

Stop-valves, gate-valves and ball-valves are all plumbing fittings that in different ways do precisely the same thing, which is to regulate the flow of water through pipes. Each of the three types of valve performs an important function in your water system, and it is therefore in your interest to know not only what they do and how they do it, but also how to put right any of the faults to which they are prone.

Stop-valves

Your main stop-valve is perhaps the single most important plumbing fitting in your house. In the event of almost any plumbing emergency the very first thing that you should do is turn it off. This will stop the flow of water into your house and reduce the extent of any damage. Looking like a very basic brass tap, your main stop-valve will be found set into the rising main not far from the point where this pipe enters your house. Often it will be located under the kitchen sink. If your house is fairly old then it could be that it won’t be provided with a main stopvalve. If this is the case, then you will have to use the local water authority’s stop-valve instead. You will find it under a hinged metal flap set into your garden path or the pavement outside your property.

This sort of stopvalve usually has a specially-shaped handle that can only be turned with one of the water authority’s turnkeys. So that you can deal promptly with any emergency you should make sure that you either have one of these turnkeys, or at least that you have ready access to one. However, both for the sake of convenience and because specialist gadgets like turnkeys have a habit of disappearing when they’re most needed, you may decide to install a main stop-valve yourself – not a difficult task if the rising main is made of copper pipe.

The internal construction of a stop-valve is identical to that of an ordinary tap, and so it is prone to the same types of faults. But one further trouble that may afflict your stop-valve – which doesn’t crop up with ordinary taps – is that of jamming in the open position as a result of disuse. It’s a problem cured simply by applying penetrating oil to the spindle. However, you can prevent this happening by closing and opening the stop-valve regularly, and by leaving it fractionally less than fully open – a quarter turn towards closure will do.

Gate-valves

Gate-valves Whereas stop-valves are always fitted to pipes that are under mains pressure, gatevalves are used on pipes that are only subject to low pressure. They are therefore found on hot and cold water distribution pipes and on those of the central heating system. Gatevalves differ from stop-valves in as much as they control the flow of water through them, not with a washered valve, but by means of a metal plate or ‘gate’. You can distinguish them from stop-valves by the fact that their valve bodies are bigger, and by their wheel as opposed to crutch – handles. Due to the simplicity of their internal construction gate valves require little attention.

Unlike stop-valves, which have to be fitted so that the water flowing through them follows the direction of an arrow stamped on the valve body, you can install a gatevalve either way round. Mini stop-valves Mini stop-valves are useful little fittings that you can insert into any pipe run. Their presence enables you to re-washer or renew a tap or ball-valve (see below) or repair a water-using appliance such as a washing machine without disrupting the rest of your water system.

They can also be used to quieten an excessively noisy lavatory flushing cistern that is fed directly from the rising main, since by slowing down the flow of water to the ball-valve you can reduce the noise without materially affecting the cistern’s rate of filling after flushing. You usually fit a mini stop-valve immediately before the appliance that it is to control; and they can be turned off and on either with a screwdriver, or by turning a small handle through 180°.

Ball-valves

Ball-valves are really just self-regulating taps designed to maintain a given volume of water in a cistern. While there are a number of different patterns they all have a float-not necessarily a ball these days – at one end of a rigid arm which opens or closes a valve as the water level in the cistern falls or rises. There are basically two types of ball-valves: the traditional type, generally made of brass, in which the water flow is controlled by a washered plug or piston; and the type that has been developed more recently in which the flow is controlled by a large rubber diaphragm housed within a plastic body.

Croydon and Portsmouth ball-valves

The oldest of the traditional types of ballvalves is the Croydon pattern. You can easily recognise one of these by the position of its piston, which operates vertically, and by the fact that it delivers water to the cistern in two insufferably noisy streams. Due to their noisiness, Croydon valves are now by and large obsolete, and if you do come across one you will almost certainly want to replace it.

The traditional type of valve that superseded the Croydon pattern was the Portsmouth valve. You can distinguish it from the former type by the fact that its piston operates horizontally; and as it is still popular with plumbers despite the development of more sophisticated diaphragm type valves, it is a pattern that you may well find in your home. When one of your ball-valves goes wrong the first thing you will notice is water dripping from an outside overflow pipe.

If the valve is a Portsmouth pattern then it is likely to have developed one of three faults. First, it could have jammed partially open as a result of the build-up of scale or the presence of grit; or, secondly, it could need re-washering. In either of these cases this will necessitate you turning off the water supply so that you can either clean the ball-valve or fit a new washer to it.

Lastly, the valve could have been incorrectly adjusted to maintain the proper water level in the cistern – which should be about 25mm (1 in) below the overflow pipe. Even modern Portsmouth valves are rarely provided with any specific means of adjusting the water level, so if you need to do so you will have to resort to bending the float arm. Noise can be a problem with Portsmouth valves. It is caused either by the inrush of water through the valve nozzle, or by vibration created by the float bouncing on ripples on the surface of the water (‘water hammer’).

As silencer tubes are now banned by water authorities, you will have to try other methods to deal with this problem. Reducing the mains pressure by closing the rising main stopvalve slightly may help, and as vibration can be magnified by a loose rising main it is worth making sure that this pipe is properly secured with pipe clips. Another measure the plumbers can take, is the use of a stabiliser for the float using a submerged plastic flowerpot tied to the float arm with nylon cord.

However, if all the above measures fail you will have to consider replacing the Portsmouth valve with one of the modern diaphragm types. Diaphragm ball-valves Diaphragm ball-valves, which are also referred to as BRS or Garston ball-valves, were specially developed to overcome the noisiness and inherent faults of the Croydon and Portsmouth valves. Since the moving parts of a diaphragm valve are protected from incoming water by the diaphragm, there is no risk of them seizing up a result of scale deposits; and the problem of noisy water delivery is often overcome nowadays by an overhead sprinkler outlet which sprays rather than squirts the water into the cistern. Should you need to adjust the water level in a cistern fitted with a diaphragm valve, then invariably you can by means other than bending the float arm.

The only problems you are likely to encounter with diaphragm valves are jamming of the diaphragm against the valve nozzle, and obstruction of the space between the nozzle and diaphragm with debris from the main. You remedy these problems by unscrewing the knurled retaining cap and either freeing the diaphragm with a pointed tool or removing the debris.