Ball valves

Ball valves are vital parts of the plumbing system in the home, since they control the amount of water in your cold water storage and WC cisterns. They must operate efficiently, otherwise the cisterns will overflow – or not fill up correctly.

wc cistern ball valve

The purpose of the bail or float, valve is to maintain water at a constant level in cold water storage and WC flushing cisterns. All ball valves have a metal or plastic arm terminating in a float (not necessarily a ball) that rises or falls with the level of the water in the cistern. As the water level falls the movement of the float aim opens the valve to allow water to flow through it: as the level rises the arm closes the valve. The old types of ball valve the Croydon and the Portsmouth control the flow of water by a washered metal plug. The main disadvantage of these is that failure of the washer or dirt or corrosion on the parts can cause leaks. Modern ball valves, which have a rubber diaphragm instead of a washered plug, are designed to overcome these problems.

Croydon and Portsmouth valves
On both these valves a washered metal plug is forced tightly against the valve seating to prevent a flow of water when the cistern is full. The plug of a Croydon moves vertically within the valve body. When the valve is open, water splashes into the cistern via two channels built into either side of the body of the valve. Croydon valves are always noisy in action and, for this reason, are now rarely, if ever, installed in homes.

The Portsmouth valve is the one now most likely to be found in installations, particularly new ones. Its plug moves horizontally within the valve body and the end of the float arm is bent over to fit within a slot built into the plug. The noise of these valves used to be reduced by fitting a silencer tube into the valve outlet. This is a plastic or metal tube that delivers incoming water below the level of the water already in the cistern; it eliminates splashing and reduces the ripple formation that is a common cause of noise and vibration in ball valves. Unfortunately water authorities no longer permit the use of these silencer tubes, since in the event of water pressure failure they could cause water from storage and flushing cisterns to siphon back into the main.

Dealing with leaks
A steady drip from the cistern’s warning pipe indicates a worn washer a common fault on the Croydon and Portsmouth valves. It may be possible to cure the leak, at least temporarily, without changing the washer simply by lowering the level of the water in the cistern. There is no need to cut off the water supply to do this: remove the cover from the cistern, unscrew and remove the float from the end of the float arm. Take the arm firmly in both hands and bend the float end downwards, then reassemble. This will keep the water below the normal level, which is about 25mm below the warning pipe in a cold water storage cistern and l3mm below the warning pipe in a flushing cistern. (If you need to raise the water level in a cistern, bend up the float end of the arm.)

Changing the washer
If lowering the level of the water does not cure the leak, you will need to change the ball valve washer. First cut off the water supply at the nearest stopcock. Some Portsmouth valves have a screw-on cap at the end of the valve body: this must be removed. Straighten and pul1 out the split pin on which the float arm pivots and remove the float arm; insert the blade of a screwdriver in the slot in the base of the valve body from which the float arm has been removed and push out the plug. The plug has two parts: a body and a cap retaining the washer, but it may be difficult to see the division between these parts in a plug that has been in use for some time. To replace the washer you will need to remove the retaining plug: insert the blade of a screwdriver through the slot in the body and turn the cap with a pair of pliers. This can be very difficult, so don’t risk damaging the plug. If the cap will not unscrew easily, pick out the old washer with the point of a penknife and force a new washer under the flange of the cap, making sure the washer lies flat on its seating.

It is important to remove any dirt on the metal parts. Before reassembling the plug, clean it with fine abrasive paper and smear with petroleum jelly.

When to replace the valve
Continued leaking after renewal of the washer may indicate the valve seating the plug has been scored by grit from the main or water outlet r valve seating water outlet a low pressure valve has been fitted where a high pressure one is required. In either case, a new valve will be needed. Ball valves are classified as high pressure (HP) or low pressure (LP) depending on the diameter of the valve seating and are usually stamped accordingly on the valve body. High pressure valves are usually installed where the water supply is direct from the main and low pressure valves where the water supply is from another storage cistern, as is usually the case with WC flushing cisterns. Using the wrong kind of valve will result in either constant leaks or a long delay in the refilling of the cistern. Where a WC flushing cistern is supplied from a cold water storage cistern only a metre above the level of the WC suite, it may be necessary to fit a full-way valve – which has a wider orifice – to ensure the cistern refills rapidly after it has been flushed.

Equilibrium valve
In some areas water pressure may fluctuate considerably throughout a 24h period. In such cases, the provision of an equilibrium valve is recommended. This valve has a wide nozzle orifice but is closed by a special plug with a channel bored through its centre: this allows water to pass through to a sealed chamber behind the valve. The plug is therefore in a state of equilibrium: water pressure is equal on each side of the plug and the valve opens only at the prompting of the float arm – not partly as a result of the pressure of water in the rising main trying to force the valve open. An equilibrium valve is also useful in preventing water hammer – shock waves produced when the conflict between water pressure in the rising main and the buoyancy of the float result in the valve bouncing on its seating.

Fitting a garden tap

Bib taps
The type used for a garden or garage water supply is usually fitted into a screwed wall plate socket. To ensure a watertight fit with a threaded joint of this kind, bind PTFE plastic thread sealing tape round the threaded tail of the tap before screwing into the socket. If, when screwed home, the tap is not upright unscrew and slip one or more metal washers over the tail you will achieve an upright fit by trial and error.

garden tap

Fitting new taps

bathroom ensuite double basin taps
Before you renew a tap the existing one has to be taken out and this can be the most difficult part of the job. The back nut, which secures the tap underneath, is likely to be inaccessible and may well be firmly fixed by scale and corrosion. Cut off the water supply to the tap and then unscrew the ‘cap and lining’ nut that connects the tail of the tap to the water supply pipe. With a basin or sink it may be necessary to disconnect the waste pipe, take the appliance off its mounting and turn it upside down on the floor in order to get a better purchase on the back nut. A cranked ‘basin spanner’ will help do this. Removal of old bath taps can be particularly difficult because of the cramped and badly lit space in which you will have to work. It may prove better to disconnect the water supply and waste pipes and pull the bath forward to give yourself more room to work.

Pillar taps
When fitting new pillar taps slip a plastic washer over the tail of the tap and insert the tail into the hole provided for it in the top of the appliance. Slip another plastic washer over the tail as it protrudes through the appliance and follow it with the retaining back nut. Where the tap is being fitted into an appliance of thin material, such as a stainless steel sink or an enamelled steel fitted basin, a ‘top hat’ or spacer washer must be used under the appliance to take the protruding shank of the tap. With an appliance of thick material, such as a ceramic wash-basin, a flat plastic washer can be used. When fitting a tap into a basin of this kind do not overtighten the back nut, since the ceramic is very easily damaged by rough handling. Pillar taps are connected to their water supply pipes by means of a ‘tap connector’ or ‘cap and lining’ joint. This incorporates a fibre washer that ensures a watertight connection.

Continued dripping

Occasionally a tap will continue to drip even after being fitted with a new washer. This indicates the valve seating has been scratched and scored by grit in the water supply and no longer gives a watertight connection. There are reseating tools available, but the simplest way to deal with this problem when it affects a conventional tap is to use a new nylon washer and seating kit. The nylon seating is placed squarely on the brass seating of the tap. Put the new washer and jumper in the headgear of the tap and screw them down hard into the tap body, forcing the nylon valve seating into position. This method cannot be used on Supataps, but the manufacturers of these taps make and supply a reseating tool for the purpose.

bathroom basin and tap

Gland failure
Another common fault in taps, gland failure, is indicated by water escaping up the spindle when the tap is turned on. The tap can also be turned on and off very easily, with just a spin of the fingers, which often causes water hammer (the effect of shock waves in the pipes produced by the sudden cessation of flowing water). Causes of gland failure may be back pressure resulting from the connection of a hose or detergent-charged water running down the spindle and washing grease from the gland packing. To adjust or renew the gland of a conventional tap, remove the capstan or crutch head by unscrewing and removing the tiny retaining grub screw.

If taking off the head proves difficult, open up the tap and unscrew and raise the protective cover as high as possible. Insert two pieces of wood (at back and front) between the base of the raised cover and the body of the tap. Then close the tap down again and the upward pressure of the cover will force off the head or handle. The gland-adjusting nut is the first nut through which the spindle of the tap passes. To tighten, tum in a clockwise direction.
Eventually all the allowance for adjustment will be taken up and the gland packing will have to be renewed. To do this, unscrew. and remove the gland packing nut. Existing gland packing material can be removed with the point of a penknife. Repack with strands of wool steeped in vaseline, press down hard and reassemble the tap. Some modern taps have a rubber ‘O’ ring seal instead of a conventional gland. These are less likely to give trouble, but if they do simply renew the ring.

Repairing taps and washers

basin with pillar taps

Pillar taps
To rewasher the conventional pillar tap, you must cut off the water supply to the tap. If the fault is in the cold water tap over the kitchen sink (which should be supplied direct from the mains) you will need to turn off the main stopcock. Other taps may have a stopcock or gate valve on the distribution pipe serving them; if so, turn off this valve. If there is no such valve, tie up the arm of the ball valve serving the main cold water storage cistern and open all bathroom taps and the kitchen hot tap to drain the cistern and distribution pipes. Unscrew the protective cover of the tap. You should be able to do this by hand, but if not you can use a pipe wrench, although you must pad the jaws to avoid damaging the chromium plating on the tap.
pillar tap diagram scheme
Insert an adjustable spanner under the base of the cover, unscrew the headgear nut and remove the headgear. The jumper (or valve) of the cold water tap over the kitchen sink will usually be resting on the valve seating in the body of the tap. Remove it, unscrew the small retaining nut and replace the washer. If the nut proves difficult to unscrew you can replace the jumper and washer complete. Some taps may have the jumper pegged into the headgear. Although it will turn, it may not be easy to remove. You may have to unscrew the retaining nut with the help of a little penetrating oil. If the retaining nut will not move, insert the blade of a screwdriver between the plate of the jumper and the base of the headgear and break the pegging. Replace the jumper and washer complete, but burr the stem of the jumper with a coarse file to ensure a tight fit. Reassemble the tap and turn on water.

Shrouded-head taps
To expose the inside of a shrouded-head tap, remove the head. This is normally done by prising off the plastic ‘hot’ or ‘cold’ label, under which there is a retaining screw. Undo the screw and lift off the shrouded-head. A few shrouded-head taps have the head retained by a tiny grub screw in the side, similar to the grub screw retaining the capstan or crutch head of a conventional tap. Others may have no retaining screw at all, in which case after they are fully opened you must give a final turn that allows the head to be pulled off.


Rewashering a Supatap is a quick job that avoids cutting off the water supply. Open the tap slightly and with a spanner unscrew and release the retaining nut at the top of the nozzle. Start turning the tap; there will be an increasing flow of water, but this will cease as the check valve falls into position. The nozzle will then come off in your hand. Tap the nozzle on a hard surface (not one that will chip) to loosen the anti-splash device in which the washer and jumper are fixed. Turn the nozzle upside down and the anti-splash will drop out. Remove the washer and jumper by inserting a blade between the plate and the anti-splash and insert a new set. Replace the antisplash in the nozzle and reassemble the tap, remembering the nozzle screws back on with a left-hand thread.

Water leaks

Plumbing job in Notting Hill, London

ceiling water stains leak
The ground floor flat had been damaged by the water leaks. Stains present on the ceiling and wall.
wall water leak damage
The plumbers removed a section of the wall and ceiling in order to find the leak source.
damaged wall by water leak
After the water leak was fixed, the Painters and Decorators were called to repair the wall and ceiling.
wall repairs, painting & decorating

Minimising flood damage

Minimising flood damage from water leaks

Often the first sign of a leaking pipe will be a spreading stain on a wall or ceiling or a puddle on the floor. To prevent further damage, shut off the water supply immediately, before trying to trace the leak and repair it. You can sometimes anticipate water damage and keep it to a minimum. Where leaking pipes are concealed above the ceiling and a water stain is visible, place a waterproof sheet on the floor and position a catch basin under the wet area.

If water is leaking from a ceiling light fitting, shut off the electricity and drain the fixture by removing its cover. Poke a hole through the ceiling or remove a section of it to let any remaining water drain out. Stand out of the way! During a plumbing freeze-up, take precautions against leaks until you can be certain the pipes have suffered no damage. Since the leaks will be frozen until,the pipes thaw, waterproof the suspect area with plastic dustsheets like those used by painters. If you spot a crack, clamp a patch on it.

And be ready with a few extra bowls and buckets in case undetected leaks reveal themselves. If you arrive on the scene too late to avert a flood, you can still construct a makeshift dam from sandbags or rolledup rugs that will prevent the flood from spreading to other rooms. For a bad flood, you may need to use a submersible pump, usually available from tool-hire firms. If the situation is desperate, call a plumber or a plumbing company, which will always help in an emergency.

Emergency Pipe Repairs – Leaks

When you discover a leak in a supply pipe, the first thing to do, of course, is shut off the water supply to the damaged section so you can proceed to plug the hole. An application of epoxy glue or plastic tape is the quickest emergency procedure. Various “bandages” or plugs are even better. But before trying any remedy, make sure the pipe surface is dry enough for adhesives or sleeves to hold. In the case of a leaking supply pipe that is not frozen, completely drain and dry the affected section if possible-an electric hair drier does a quick job. Damaged pipes that are frozen should be left unthawed and undrained until patching is completed. Waste pipes and traps, unlike supply pipes, are not under pressure and normally contain no water (apart from the trap seal) when not in use.

Larger Leaks
A hose patch.
An effective temporary patch can be made by splitting a section of rubber hose lengthwise so that it will fit round the pipe. Strong, flexible wire, such as that used for hanging pictures, will serve to secure the hose-make a series of loops along the patch, spaced about 25mm apart, and twist each loop tight with a pair of pliers.

Tiny Leaks
Plugging o hole with o pencil.
A good emergency plug for a small leak in a supply pipe is a pencil point jammed into the hole and broken off; the soft graphite point will conform to the shape of the opening and seal the leak.

Securing the plug. Dry the surface of the pipe if after the leak has been plugged, then roll heavy tape over the damaged area to hold the plug in place. Wrap the tape several centimetres to the left and the right of the leak.

Securing hose with jubilee clips.

To fix a hose patch with uniform pressure, use jubilee clips as on a motor car hose. These clips can be adjusted to fit virtually any diameter of water pipe. It is best to install at least three clips over the patch.

Epoxy Adhesive
Coating and bandaging o split.
Epoxy glue makes a useful emergency repair for a cracked pipe. First drain and dry the damaged pipe. Mix the glue-available in kit form from plumbers’ merchants according to the instructions and spread it generously over and around the crack. Bandage the pipe tightly with nylon or fibreglass tape and apply a second layer of adhesive. Leave the patch to dry.

Binding threaded pipes.
If a leak appears at a threaded joint, drain the pipe, dry the damaged area and apply epoxy cement over the leaking joint. Allow the epoxy to harden completely, according to the manufacturer’s instructions, before restoring water pressure. Epoxy also can be used on plastic joints.

Fixing o lead caulked joint.
If water seeps from a lead-caulked spigot and socket joint, use a hammer and chisel to tamp down the lead inside the socket of the pipe. Since the lead is soft enough to be reshaped over the weak spot, this simple procedure often is sufficient to reseal the joint. Check first, however, that the leak is not due to a crack in the socket. If it is, the pipe will probably need replacing, since tamping down the lead might simply widen the crack and worsen the leak.

Water supply & drainage system

water supply drains london system

The diagrams for typical household pipe systems for the two principal forms of water supply and drainage found in the United Kingdom and London. Both supply systems may be found with either one of the drainage systems. (Pipes for central heating, are not shown.) The details of the piping will vary from house to house according to the location of appliances, but the main features are constant. Track the layout of the pipes in your own home before you attempt any repairs or alterations.

The supply system may be either direct or indirect.

In the direct type, the mains water is conducted through the vertical pipe known as the rising main straight to the cold taps and appliances throughout the house; in the indirect system, the rising main fills a cold water storage cistern located above the hot water cylinder-usually in the roof space-and water is then drawn from the cistern to supply the needs of the household. In this scheme, the law requires that one tap (usually in the kitchen) should always be supplied direct from the mains, so that the occupants can drink water that has not been exposed to airborne bacteria while stored in the cistern.

A second mains tap is permitted but not required; all others must be drawn from the cistern. The service pipe by which the water supply enters the house from the public water main is controlled by a stoptap designed to act also as a non-return valve. This is a precaution against the accident of back-siphonage, whereby an unexpected drop in mains pressure might, in unusual circumstances, allow contaminated water from an appliance within the house to be siphoned back into the mains, where it could pollute the supply. If the stoptap is outside the boundary of the property, it belongs to the water authority; if inside, it is the householder’s responsibility. Just inside the house is usually another stoptap, with which the owner can interrupt the flow into the household system, for instance before dealing with a leak.
It is useful to have stoptaps and valves at other points in the system as well, so that you can isolate and drain different sections of piping when you want to work on them. The drainage system may be either the single-stack type , in which W.C.s and all other appliances empty into the same soil and waste stack, or double-stack, where the soil stack for sewage is separate from the waste stack for water from baths, basins and sinks. All soil stacks, whether separate or combined, have a vent above roof level, to keep air flowing through the system. So that the sewers will not be overburdened by sudden storms, surface water-rain-sometimes flows through gutters and a trapped gully into a separate drain.

The direct system.
In a direct supply system, the cold water storage cistern feeds only the hot water cylinder, while all the cold taps, W.C. cisterns and other appliances are supplied under mains pressure. The double-stack drainage system, common in older houses, has a soil stack carrying sewage and a separate waste stack for to other household wastes, both positioned against the external wall of the house. They are usually constructed of cast iron, but many have been replaced by PVC at some time when they needed repair. The waste stack can be an open hopper head, but it could also be a sealed pipe, vented at roof level, like the soil stack.

The indirect system.
In a typical indirect supply system, only the kitchen cold tap and a garden tap are connected direct to the mains. The remaining taps and appliances, and the hot water cylinder, are fed from the cold water storage cistern. The single combined soil and waste stack, normally built of PVC piping, is located inside the house. The water from the kitchen sink is shown discharging into its own trapped gully; however, it might equally well feed into the main stack like the rest of the appliances in the house.

Spanners and wrenches for plumbing

Tools for plumbing
plumbers tools

1. Socket set.
Some of the accessories used with the socket set are the tee bar wrench (2), the rachet handle (3) and the extension bar (4). Sockets are available in the following thread styles:- American Fine (AF), British Standard Whitworth (BSW), Iso metric (M) and British Association (BA). Sockets for the last thread style are very small. These tools are used for loosening nuts and, providing you use the right size socket, the tool will not slip. There is, therefore, less chance of damaging the head of the nut than with a spanner. You can also achieve greater torque, or circular force, with these tools than with a spanner. Other accessories for the socket set are speed braces and the universal joint. These allow the sockets to be used in awkward positions. A torque wrench (not shown) can be calibrated to allow nuts or bolts to be tightened to a specific pressure. Socket sets are fairly expensive to buy but, as with most of the tools shown here, they can usually be hired.

2. Tee bar wrench.
3. Rachet handle.
4. Extension bar.

Pipe wrenches.
These types of pipe wrench are available in lengths ranging from 150mm to 1000mm and will cope with pipe sizes ranging from 13mm to 150mm diameter. These wrenches are mainly used for work on iron pipes – they can easily damage softer metals like copper and brass. The head is sprung loaded and this, together with the toothed jaws, enables a strong grip to be exerted on round pipe sections as opposed to hexagonal nut sections.

7. Adiustable wrench or spanner.
This is a very useful tool, particularly for copper plumbing. They are available in a range of lengths from l00mm (4in) to 500mm (20in) with jaw opening of between 13mm to 163mm. Do not use this wrench on fine engineering nuts or bolts of the type used, for example, for automobile assembly. The jaws are too large for such nuts which can easily be damaged – and this could result in the loosening of these nuts and bolts and the creation of a potentially dangerous situation.

8. Chain wrench.
This is an easily adjustable wrench for shifting heavily rusted or encrusted iron pipe joints. It is lighter to use though less effective than the heavy duty pipe wrench. Available in handle lengths of between 300mm and 450mm.

9. Universal gripping and clamping tool.
This tool has a variety of trade names including Mole and Grip-Lok. Available in a wide variety of shapes and sizes. An attachment is available which allows the tool to be used as a mini bench vice.

10. Slip joint pliers.
This tool has a thin section to allow the nose to slip into tight places. It has two jaw opening positions and a shear type wire cutter.

11. Needle nosed side cutting pliers.
These are used for fine wire work. Radio pliers are the same except that they have insulated handles.

12. Electrician’s or combination square nosed pliers.
These are heavy duty pliers with a square nose and serated hole – both of which can be used for holding small diameter tubing and nuts and bolts. Usually this tool has two types of wire cutter, a shear cutter and a side cutter. The handles are insulated but make sure when you buy this tool that the handles are guaranteed to withstand any voltage with which the pliers are likely to come into contact.

13. Round nosed pliers.
These pliers do not have a great deal of domestic application but are useful for coiling or twisting wire.

14. Water pump pliers.
These are adjustable pliers with up to six different jaw positions. They are general purpose pliers useful in plumbing.

15. Scotch gas pliers.
These are general purpose pliers, used where a light but firm grip is needed.

16. Open ended spanners and wrenches.
These are available in every nut and thread size encountered.

17. Ring spanners.
It is preferable to use these spanners wherever possible as they are far less likely to slip than open ended spanners. You can also obtain greater torque with these spanners.

18. Combination spanners.
These tools have an open spanner at one end and a ring spanner at the other. For a complete set you will obviously need twice as many spanners than for a full set of ring or open ended spanners.

19. Allen keys or hollow head wrenches.
These are used with hexagonal hollow headed screws.