Taps and Mixers

The tap is the basic piece of plumbing equipment. A plumber of the early 1900s, confronted with the taps of today, would find that the differences between these and the old brass taps to which he was accustomed, are more apparent than real.

Although there have been tremendous changes in appearance and design, most modern taps operate in exactly the same way as the bib-cocks that can still be seen protruding over the kitchen sinks of 1914 houses.

Taps are described as ‘bibs’ or ‘pillars’. Bib taps have a horizontal inlet and pillar taps a vertical one. Pillars are now used for most purposes within the home while bibs are most likely to be found nowadays providing a garden or garage water supply. Water flows into the body of the tap via a threaded ‘tail’ connected to the distribution pipe. It passes through the valve seating and leaves by the spout. Into the tap body is screwed the ‘headgear’, a fibre body washer between the two parts of the tap. ensuring a watertight joint. The spindle, with a crutch or capstan head, passes through the headgear. Turning the spindle opens or closes the tap by raising or lowering a washered valve or jumper onto the valve seating. When the tap is turned on water is prevented from escaping up the spindle by a gland or stuffing box, packed with greased wool, through which the spindle passes.

Most modern taps have an easy-clean cover that conceals the headgear and many have ‘shrouded heads’. With such taps the headgear and the head or handle appear to comprise a single unit.

Bath and basin mixers are, in effect, two taps with a single spout. Adjusting the two heads produces a single stream of water at the required temperature. Many bath mixers incorporate an upper outlet to supply a flexible shower hose. A switch is provided to direct the mixed water either upwards to the shower or downwards into the bath as required. Some modern basin mixers incorporate a ‘pop up’ waste. These units dispense with the usual waste plug and somewhat unsightly chain. Pressure on a knob in the centre of the mixer activates a rod and causes the waste plug to ‘pop up’ and allow the basin to drain.

Sink mixers are different in design from those used for basins and baths. This is because it is illegal to mix in one fitting water direct from the main and water from a storage cistern. Consequently sink mixers have separate channels for the hot and cold water passing through the tap body and spout. Hot and cold water mixes in the air after leaving the spout.

Rewashering is the most common maintenance job required on taps. The need for rewashering is indicated when the tap becomes more and more difficult to turn off fully. Eventually, however hard the head is turned, there will still be a steady drip from the spout.

To rewasher any tap of the kind described above the water supply to it must first be cut off. With the cold tap over the sink this is done by turning off the householder’s main stopcock. It may be possible to turn off the supply to the hot taps and the bathroom cold taps by turning off any gate valve or stop-cock in the supply pipe. If there is no such control valve the best course of action is to tie up the float arm of the ball valve supplying the main cold water storage cistern and drain this cistern and the distribution pipes. This can be done from the bathroom taps.

Where both hot and cold bathroom taps are supplied from a storage cistern there is no need to drain the hot water from the hot water storage cylinder even if it is a hot tap that is to be rewashered. Turn on the bathroom cold taps and leave to drain. When no more water flows from them turn on the tap to be rewashered. Only the few pints of water in the distributing pipe will drain away. The storage cylinder will remain full of hot water.

Unscrew and raise the easy-clean cover. It should be possible to do this by hand. If it is necessary to use a wrench pad the jaws to avoid damaging the chromium plated surface. Insert the wrench under the easy-clean cover and turn the hexagonal nut at the base of the headgear. This will unscrew to permit the headgear to be lifted off the tap body. When the headgear is removed the valve, with its washer attached, of a kitchen sink cold tap will be found to be resting on the valve seating. A small retaining nut holds the washer onto the valve. This must be removed or a new washer and jumper complete can be used as a replacement.

Valves of hot taps and bathroom cold taps may be found to be ‘pegged’ into the headgear of the tap. The valve will turn freely but cannot be removed without breaking the pegging. In such a situation every effort must be made to unscrew the washer retaining nut. A drop of penetrating oil will often loosen it sufficiently to enable it to be unscrewed with a spanner of the correct size. If this proves to be absolutely impossible the valve can be removed from the headgear by inserting a screw driver blade between the valve plate and the headgear to break the pegging. The stem of any replacement valve should be scored with a rasp to give a moderately tight fit. /. Turn off water supply and open tap or valve fully. Fit waste plug in sink. Wrap rag round shield and loosen it with adjustable spanner if there are flats – if not use a pipe wrench very gently. 2. Unscrew the shield fully and loosen hexagonal nut securing head using adjustable spanner. Unscrew the nut by hand and lift the head of the tap out of the body. 3. With some taps the jumper can be removed – on others it fits loosely. The washer is usually held against the jumper plate by a small nut. Some taps used a domed washer fixed to the jumper – in this case the jumper is replaced. 4. Grip the edge of the jumper plate with pliers and undo the nut with a small spanner. Turn the nut gently – it often gets fouled with fur and scale. If the nut cannot be removed the whole jumper will have to be replaced. Either the same type or a domed jumper can be used. 5. Remove the nut and the metal washer. The old washer is replaced by the new one, fitted with the side with the maker’s name against the jumper plate. Replace the metal washer and nut and tighten securely. 6. Reassemble the head into the body as it was removed, screw down carefully by hand and tighten with the adjustable spanner. Screw down the shield – hand tight only – and turn on the water supply

Continued dripping after a washer has been renewed suggests that the valve seating has been scored and scratched by grit from the main. The tap can be reseated using a special tool or, alternatively, a nylon washer and valve seating kit can be used to fit a new nylon seating over the old brass one.

The way in which the head of a shrouded head tap is removed to give access to the interior for rewashering depends upon the make of the tap. Some models have a retaining screw concealed under the plastic ‘Hot’ or ‘Cold’ indicator. Prise off this plastic disc, undo the retaining screw and the head will lift off, revealing a headgear similar to that of the traditional tap. Other models have a small grub screw in the side of the shrouded head. The shrouded head of one of the taps in the Deltaflow range is removed by turning the tap fully on. Then the head is given a final turn and can be pulled off in the hand.

A number of taps have been produced with the object of eliminating the need to cut off the water supply before rewashering. Only one of these-the supatap-has stood the test of time. Supataps are turned on or off by turning the nozzle of the tap itself. Ears of kemetal plastic are provided to enable this to be done easily and comfortably.

Supataps are rewashered by first unscrewing and disconnecting the retaining nut at the top of the nozzle. Then open the tap and keep on turning the nozzle. At first water flow will increase but will then stop-just before the nozzle comes off in your hand-as a check valve within the tap falls into position. Tap the nozzle end on a hard surface— not the glazed surface of a ceramic sink or basin!-and turn it upside down. The anti-splash device, into which the valve and washer is fitted, will then fall out. Prise out the valve and fit a replacement. When re-assembling the tap remember that the nozzle screws in with a left hand thread. It must therefore be turned in the opposite direction from that dictated by instinct.

Leakage up the spindle of a tap when the tap is turned on indicates failure of the gland or stuffing box. It may be accompanied by water hammer—since the tap can be ‘spun’ on and off much too easily-and often results from the connection of a garden or washing machine hose having been connected to a kitchen tap so as to produce back pressure. /. Hold the nozzle in one hand and loosen the gland nut with a spanner. 2. Hold the gland nut and unscrew the nozzle fully. See that the check valve drops into position. 3. Tap the nozzle on a firm surface to loosen the anti-splash. 4. Turn the nozzle upside down and push out the ami-splash. 5. The jumper may be stuck in the anti-splash, but can be gently levered out with a coin or blade 6. Put a new jumper into the anti-splash and make sure it clicks home. 7. Drop the anti-splash into the nozzle, washer uppermost. 8. Refit the nozzle to the tap and screw up by hand. 9. Holding the nozzle, tighten the gland nut and ensure that the tap works properly and does not drip

Fig. 4.6. Replacing the washer on a Supatap. It is not necessary to turn off the water supply to do this as a check valve does it automatically when the tap is dismantled

First try adjusting the gland nut. This is the first nut through which the spindle of the tap passes. It may be possible to reach it, without removing the tap head, by opening up the tap fully and raising the easy-clean cover as far is it will go. Half a turn, or a turn, in a clockwise direction may remedy the leakage.

Eventually all the adjustment will be taken up and the gland will need repacking. There is no need to cut off the water supply to the tap to do this. Unscrew the grub screw retaining the crutch or capstan head and tap the head upwards to remove it. Remove the easy-clean cover. Unscrew and remove the gland nut and pick out all existing gland packing material with the point of a penknife blade. Repack using household wool steeped in petroleum jelly. Caulk down firmly and reassemble the tap. In some modern taps an ‘O’ ring seal replaces the conventional gland. It is interesting to note that the modern shrouded head was not, in the first instance, introduced for the sake of its appearance, but in an attempt to prevent gland failure. It had been noted that housewives frequently turned taps on and off with hands dripping with household detergent. This detergent ran down the spindle of tap into the gland, from which it quickly washed the grease out of the packing.

Poor or intermittent flow, particularly from hot water taps, is more likely to be due to an air lock in the distribution pipe than to a fault in the tap itself. Air locks can usually be cured by connecting one end of a length of hose to the cold tap over the kitchen sink and the other end to the tap giving trouble. Turn both taps on and the mains pressure from the kitchen cold tap should blow the air bubble out of the system.

Constantly recurring air locks are caused by design faults that should always be investigated and remedied. The commonest single cause is too small a cold water supply pipe from the cold water storage cistern to the hot water cylinder. If this pipe is only 15mm in diameter it will be incapable of replacing hot water drawn off by a %in bath tap. Water level will fall in the vent pipe until air is able to enter the distribution pipe to produce a blockage.

Sometimes the supply pipe is of adequate diameter but a gate valve of a smaller size has been fitted into it. Alternatively a gate valve of the correct size may have been left partially closed after a piece of maintenance has been carried out. Other possible causes of recurring air locks are a cold water storage cistern of inadequate capacity or one fed by a sluggish ball valve. All ‘horizontal’ lengths of distribution should, in fact, slope slightly upwards towards the cold water storage cistern or the hot water vent pipe. This will permit any bubbles of air that may gain access to escape.

At the time of writing taps have not yet been metricated and are still to be found in builders merchants’ catalogues designated as ‘Ain and %in. There is however a growing tendency to refer to them metrically by the metric size of the copper tubing to which they are to be connected. Thus sink and basin taps are given a nominal size of 15mm and bath taps one of 22mm although these dimensions represent no actual measurement of the taps themselves.

Before fitting a pillar tap a plastic washer is slipped over the tail of the tap to protect the surface of the fitting from the metal base of the tap. Alternatively the tap may be bedded onto linseed oil putty or a non-setting mastic such as the plumber’s mait. Another plastic washer should be provided under the fitting before the back nut is tightened up. For fittings of thin materials a special spacer washer -sometimes called a ‘top hat’ or ‘cap’ washer—is needed to accommodate the protruding shank of the tap. The tail of the tap is then connected to the water supply pipe by means of a tap connector or ‘cap and liner’. This incorporates a fibre washer to ensure a watertight connection. The cap and liner may have a compression or capillary joint outlet for connection to copper or stainless steel tubing or a plain outlet for connection, by means of a wiped soldered joint, to a lead supply pipe.

Bib taps are most likely to be fitted into a wall plate elbow. The wall must be drilled and plugged and the elbow screwed to it. Before screwing in the tail of the tap p.t.f.e. plastic thread sealing tape should be bound round the thread of the tap’s tail to ensure a watertight joint. in length and from 700mm to 800mm in width is likely to remain the most popular choice for the average British householder.

Size will be dictated by the space available though the prudent purchaser will also bear in mind the additional fuel cost of filling one of the larger baths with warm water. Colour -and there is a wide colour range available-will depend upon the overall décor of the bathroom. It is with regard to the material of which the bath is made that the purchaser has greatest freedom of choice.

The traditional material is enamelled cast iron. Any bath installed more than twenty to twenty five years ago will certainly be of this material. The fact that there are still so many of them installed and in regular use is a tribute to their strength and toughness. They have disadvantages though. They are extremely heavy. Installing one is certainly not a one man job. The thick iron of which they are made tends to conduct away heat, quickly cooling the water run into them. Once the enamelled surface is damaged renoJadon can be extremely difficult ii: not im^ossi a corrosion can attack the metal underneath. They are also, oy most people’s standards, very expensive.

For all of these reasons the cheaper, lighter and more easily installed enamelled pressed steel bath enjoys considerable disadvantage is its liability to accidental damage via transport or installation. To overcome this objec-Ln one oath manufacturer a ‘supersteel’ bath, backed by guarantee, made 5 2’I gauge steel. These baths show a steady increase u,> popularly and offer many advantages to the householder and to the pro £2>nal or d.I.y. installer. Tough and hard weanng, Uujy are also extremely light in weight and easy to handle. It:» well within the capacity of one man to unload one from the delivery vehicle, carry it upstairs to the bathroom and install it single-handed. They are available in a wide range of colours and the colour extends throughout the material. Small surface scratches can be polished out without trace. Acrylic plastic has good insulating properties retaining the heat of the bath water and remaining comfortable to the touch. It is possible to purchase acrylic plastic baths with a flat, non-slip, base that eliminates a frequent cause of home accidents among the elderly.

Acrylic plastic baths are supplied with strong metal or wooden frames and cradles that should be assembled and secured to wall and floor exactly as indicated in the instructions of the manufacturer. Felt padding is provided at points of contact. These padded cradles eliminate the sagging and creaking when filled that occurred with early models of this kind of bath.

Acrylic plastic can be permanently damaged by extreme heat. When working with a blow torch in a bathroom fitted with a bath of this material keep the blow torch flame well away from the bath. Similarly the householder should make sure that all members of his family, and visitors, are made aware that placing a lighted cigarette, even briefly, on the bath rim, can cause irreparable damage.

When fitting a bath of any kind the cramped space available at the end of the bath should be borne in mind. Carry out as much of the plumbing work as possible before moving the bath into position. Have the hot and cold water supply pipes in position with their tap connectors fitted. The trap should be connected to the waste pipe with its flexible overflow pipe ready for connection to the bath overflow. It is wise to use a plastic trap and waste pipe with an acrylic bath. There will be some movement as the bath fills with hot water and a rigid metal trap and waste pipe could cause damage.

Having moved the bath into position, make the plumbing connections in logical order so as to make the most of the limited space available. First connect the trap to the waste outlet. Then connect the further tap to its supply pipe. Next make the overflow connection and finally the connection of the supply pipe to the nearer tap. All that will then remain is to fit the bath panels and to fill the gap between the side of the bath and the wall with a suitable mastic filler.

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