Stop that Dripping Tap

Plumbing equipment in the home is rarely noticed or appreciated until something goes wrong. Regular routine maintenance is needed where there are moving parts such as taps, stopcocks, flushing and cut-off valves. The dripping tap and the faulty overflow are two common problems; repair is normally straightforward with no major domestic disruption.

Plumbing maintenance may have to be carried out from time to time, particularly on those sections of a system which consist of moving parts, such as taps and the mechanism of cisterns. It is desirable to inspect these moving parts periodically to ensure that they are running efficiently.

Taps and stopcocks

The most common and irritating fault is that of the dripping tap. Taps are highly efficient, but are put to constant use and remain one of the most vulnerable parts of any system.

There are two basic types of tap-the bib tap, which has a horizontal water inlet, and the pillar tap, with a vertical inlet.

Both work on the same principle. A resilient washer is pressed down over the valve seat when the tap is turned down, preventing water from flowing from inlet to outlet.

This washer sits loosely at the base of the spindle; the handle attaches to the spindle. When the handle is turned, the spindle rises, allowing the water pressure to lift the jumper and water to flow.

One type of jumper does not, in fact, ‘jump’, since it is attached to the spindle by a press fit. This is used in situations where water is at low pressure and would not raise a conventional jumper.

This washer is the weak part of the system. It may become worn, or the valve seat become partially obstructed as a result of foreign particles preventing the washer from correctly seating, leading to the familiar drip.

Before you dismantle a dripping tap, first turn it on fully, as the sudden force of water may dislodge an obstruction. If this fails, you will have to turn off the water main and dismantle the tap.

Before starting, assemble all the tools and materials you may need, so as to minimize domestic dislocation. Where a kitchen tap is concerned, you should turn off the main stopcock.

This stopcock also should be inspected occasionally. Never leave it fully opened, or it may jam. Grease the stem periodically to ensure that it can be operated quickly and smoothly in the case of an emergency.

Draining down

Though the kitchen tap is the most used and the one most likely to need attention, where hot or cold taps are supplied from a storage cistern, it is best to shut down the supply between taps and supply to avoid draining down the storage cistern.

Hot taps can normally be isolated by shutting down the valve in the cold feed to the hot-water cylinder. If, however, there is no valve, the hot cylinder will only have to be partly drained, by drawing off the ‘crown’ of water in the cylinder.

To isolate cold storage supply, either shut down the main stopcock or tie up the ball-valve in the cistern and open all taps.

One type of tap where it is not necessary to turn off the water supply to repair the tap, is the ‘Supatap’.

Dismantling the tap

Once the system is drained, remove the tap cover. This should only need hand pressure, but if you have to use a wrench or a spanner first wrap a cloth round it to protect the surface of the tap from damage or marking.

If the cover is difficult to remove, clean the threads and smear lightly with petroleum jelly.

Beneath the cover is the headgear. Its hexagonal nut should be loosened to expose the washer on the valve seat. If the jumper is of the low-pressure pattern, it will come off with the spindle.

Jumpers are usually made of brass and the washer secured to this with a brass nut. This can seize up, and as it may distort as you try to free it, have a spare jumper and washer set handy.

Grease the threads of the nut when screwing down the new washer, and this will give ease of movement. Not all washers are suitable for both hot and cold taps, so check that the washer is correct. However, synthetic rubber washers are suitable for both, and an oversized washer can be easily trimmed to fit.

If water is by-passing the washer, the valve seat, on inspection, may be found to be worn and pitted and have to be re-ground. Usually, this is a specialist job requiring special tools. You can, however, use a nylon washer and seat set which fits over the existing valve seat to effect a repair.

Where water trickles over the top of the tap cover, this suggests that a leak has developed through the gland. The tap handle may then have to be removed.

Take out the small grub screw which holds the handle to the spindle and put it safely on one side. Insert a piece of wedged hardwood between the handle and the cover to free a sticking handle.

Unlock the gland screw and remove old packing, replacing this with wool, cotton wool or string soaked in grease, such as petroleum jelly or tallow.

Compress this into the stuffing box, leaving enough room to enable the gland screw to be tightened securely on to its thread.

Avoid overpacking the stuffing box as this will make the tap difficult to turn. To stop future leaks, give one or two extra turns on the gland screw.

10. November 2011 by admin
Categories: Featured, Handyman Tips | Tags: , , , , , , , , , | Comments Off on Stop that Dripping Tap


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