enters the cylinder from the cistern after a flush, these being placed immediately in front of the piston when this is in its normal posi- tion of rest. When a flush is required a movement of the handle, H, causes the piston to move to the left, covering up the holes and driving water up the short leg of the siphon. The piston travels a small distance past the short leg of the siphon, so that the whole body of water in the cistern, entering the cylinder at its open end, can pass over the siphon, to be discharged by the long outlet leg to a connection at the back of the pan. As long as the flush continues the rush of water along the cylinder will keep the piston at the far end of its stroke, even if the handle is released: when the flush has stopped the counterpoise weight W will cause the mechanism to return to the position shown in Fig. 240. Low-level cisterns are very popular to-day, partly perhaps because they are so accessible for adjustment or repair. They have not quite the head of water of the high-level tank, but this is partly made good by the fact that a more direct flush can be obtained, with only one easy bend, and partly by using a flush- pipe of rather larger diameter—say 1} inches instead of 1} inches; it is also an advantage to have a tank capacity of 2} or 3 gallons instead of the normal 2 gallons. Most water companies and boards permit only 2 gallons when water is paid for by “rate”, and make a surcharge of from 5s. to 10s, a year for each W.C, using a bigger cistern. The apartment needs to be a trifle longer from back to front than is normally necessary, owing to the space taken by the cistern. Low-level cisterns are suitable for either wash-down or siphonic pans.<Callout type="tip" title="Tip">Low-level cisterns offer easier access for maintenance and repairs.</Callout> Time of Discharge and Refill. A two-gallon water-waste preven- ter should discharge in about five or six seconds, and refill in from a half to one minute, the longer of these periods being allowed if it is desired to avoid noise.<Callout type="important" title="Important">Ensure proper installation of water waste preventers for efficient operation.</Callout> Flushing Valve Closets. The method of flushing a valve closet is necessarily different from that applicable to closets with a free outlet. Fig. 243 shows the arrangement in outline. The outside line shows an iron frame. It carries a handle, H, to which a lever, L, is connected, the lever controlling the water inlet to the pan. On pulling up the handle the water is turned on, and as the lever, L, falls by reason of the weight, W, it is gradually shut off. It would be instantly shut off but for the bellows regulator, B.R. This consists of a cylinder containing a small leather bellows connected to a spindle, S, the bellows having a valve at the bottom. The spindle passes through the bellows and collapses it as the handle is raised, and the descent of the spindle can be retarded to any extent by means of a small tap fixed near the top of the cylinder. Other forms of regulator are used, but that described is the most usual.<Callout type="warning" title="Warning">Improperly adjusted regulators can lead to water wastage.</Callout> Some forms of inlet valve do not require regulators, but they are usually complicated in construction and liable to get out of order. Fig. 244 shows the construction of the usual form of water inlet for a valve closet. It will be seen that it is opened by the raising of the lever and closed as the lever goes down again.<Callout type="gear" title="Gear">Valve closets require specific regulators to ensure proper flushing.</Callout> W.C. Flushing Valves. Water-closet flushing valves of excellent design and workmanship, for flushing ordinary wash-down and siphonie types of pan, are on the market and the arrangement of a W.C. apartment so provided is shown in Fig. 253. These make the use of a W.W.P. cistern unnecessary. They are very neat and efficient, and can be adjusted and sealed by a water company so as to pass 2 gallons (or other prearranged amount) each time a button or lever is pressed.<Callout type="tip" title="Tip">Modern flushing valves reduce the need for traditional cisterns.</Callout> They do not make much headway, except with property owners providing their own water supply, owing to the fact that most water companies are rightly jealous of the purity of their supplies and consequently ban any water-valve or other fitment which might result in the least fear of “ back-siphonage” from the fitting into the mains. The makers claim that a chamber provided in the valve makes such back- siphonage quite impossible, but they have not—to date—been able to persuade the Metropolitan Water Board and others to relax the regulation prohibiting the use of such valves by their consumers.<Callout type="risk" title="Risk">Back-siphonage risks can lead to contamination.</Callout> Lavatory Basins. Lavatory basins may be made of earthen- ware, fireclay, stoneware or vitreous china. B.S.S. 1188 specifies a size of 25 inches by 18 inches for general use, or 22 inches by 16 inches for use where space is limited, while the requirements of a good basin are indicated in Code of Practice 805 (1952) (Sanitary Appliances). The most important point in their design is that the overflow shall be readily accessible for cleaning. Fig. 245 shows a common form of overflow which is quite inaccessible, while Fig. 246 shows one which is nearly as bad.<Callout type="warning" title="Warning">Inaccessible overflows can lead to hygiene issues.</Callout> If in an open recess, the tube can hang on a hook and be readily lifted off for cleaning. Slot Overflows. ‘The most popular form of overflow to-day has a rectangular slot opening into the overflow tube instead of small perforations. It is shown at Figs 250, 251. This form is recommended by the Code of Practice mentioned above, but the form shown in Fig. 248 is much more accessible for cleansing.<Callout type="important" title="Important">Choose basins with easily accessible overflows to ensure proper cleaning.</Callout> The overflow channel terminates in a ring groove round the out- let so that the overflow water can always find its way out of the trap and waste-pipe below. Weir Overflows. A good form of overflow is that known as a weir, two varieties of which are shown in section in Fig. 247. In both these cases the overflow bends round to join the outlet of the basin.<Callout type="tip" title="Tip">Weir overflows provide better drainage and are easier to clean.</Callout> A much better form is shown in Fig. 248, the overflow being larger, and leading straight down to the mouth of the trap below the fitting. It need hardly be said that the overflow is not the full width of the basin, but merely consists of a recessed cham- ber. The entrance to the overflow is often guarded by a brass or nickel-plated grating, hinged to the basin. An excellent but more expensive form of waste and overflow is shown in Fig. 249. Both overflow and outlet are guarded by gratings.<Callout type="gear" title="Gear">Gratings protect overflows from blockages while allowing easy cleaning.</Callout> Behind the outlet opening is a plug, capable of being moved backwards and forwards by a lever handle at the top of the spindle, S. When the waste outlet is opened by a turn of the handle, the plug, through the agency of a crank at C, passes back into a recess, R, leaving both outlet and overflow fully open. It will be seen, too, that the overflow passes vertically down to the trap and is quite accessible. Its cost is likely to prevent its general adoption.<Callout type="risk" title="Risk">Higher costs can limit access to better sanitary fittings.</Callout> “Gate”? Type Waste and Overflow. Quite a different kind of waste and overflow is shown in Fig. 256 of the type known as a gate waste. Across a recess in the back of the basin is a plate of metal or vulcanite, sliding in grooves and shown by a thick line in the sketch. An overflow opening is cut in it as at O, and the lifting of the plate allows the water to run away.<Callout type="important" title="Important">Gate waste systems are effective but can be more expensive.</Callout> On removing the plate the whole of the overflow passage is accessible. In the particular example shown, the trap is partly formed in the basin itself to obviate the existence of even the short length of pipe that would otherwise occur above the trap and be liable to become fouled.<Callout type="tip" title="Tip">Integrated traps reduce the risk of blockages.</Callout> “Tip-up” Basins. The arrangement of the “tip-up” type of lavatory basin is shown by a line diagram in Fig. 257. The cham- ber below the basin, and the underside of the latter, are apt to become coated with dirty soap suds and, while this can be readily removed by lifting the basin out, a fitting which requires no such attention is obviously preferable, and it must be considered an undesirable type.<Callout type="warning" title="Warning">Tip-up basins require regular cleaning and maintenance.</Callout> Fixing of Basins. Lavatory basins should be fixed on brackets or cantilevers, so that the space below them is uninterrupted and accessible, and the wall behind them should be faced with non- absorbent material, such as tiling.<Callout type="important" title="Important">Proper installation ensures easy maintenance of lavatory basins.</Callout> An alternative fixing—a little more expensive—is to support the basin on a pedestal of the same material as the basin. This gives a neater appearance, but an opening has to be left at the back of the pedestal at the top for the plumber to gain access to the water-supply and waste-pipe joints and provide a catchment for dust which is quite inaccessible for cleaning.<Callout type="risk" title="Risk">Pedestal installations can make maintenance more difficult.</Callout> Still another method is to support the basin on a metal frame with adjustable legs resting on the floor. Only two legs are necessary and this method leaves better access to the pipe by the plumber and to the floor by the housemaid, while the floor covering can be slipped under the base of the legs when the adjusting screws are removed and the set screws can then be screwed up to give proper support afterwards.<Callout type="tip" title="Tip">Adjustable metal frames provide easy access for maintenance.</Callout> Basins in Bedrooms. A prominent feature of late years has been the tendency to fit lavatory basins in bedrooms. From a purely sanitary point of of the best. Great care, however, must be taken to choose a basin with a sanitary type of overflow and the trap must be of anti- siphonie or “rescaling” type unless the trap is provided with an anti-siphonage pipe which is difficult to mask and makes the plumbing more obtrusive; these will be described later in this chapter.<Callout type="warning" title="Warning">Bedroom basins require careful design to prevent contamination.</Callout> Lavatory Ranges. For schools, offices and other buildings where a number of basins is required, it is often an advantage to arrange the basins in a double row in the centre of the floor in the form of an island. A dwarf wall is built up to the level of the range of basins to provide support.<Callout type="important" title="Important">Lavatory ranges improve efficiency and reduce water usage.</Callout> The plumbing can then either be left open in the ordinary way or the wall can be made wide enough to enclose a plumbing cavity in its centre with a neat enamelled steel short cover along the top for inspection. This arrangement leaves the walls of the apartment free for the accommodation of urinal stalls, W.C.’s, ete.<Callout type="tip" title="Tip">Lavatory ranges streamline plumbing and reduce clutter.</Callout> Baths. The general principles of the design of baths are similar to those for lavatory basins. There should be a good-sized waste outlet and an accessible overflow. While lavatory basins are now almost invariably of glazed fireclay or vitreous china, there is a much larger selection of materials in the ease of baths.<Callout type="important" title="Important">Baths require careful design to ensure proper drainage.</Callout> They have been made of tinned copper, cast-iron either paint-enamelled, stove-enamelled, or porcelain-enamelled, of white glazed fireclay or earthenware, or of marble. The obsolete copper bath took very little heat out of the water, but required to be carried on cradling in order to be strong enough to stand the weight of the water and of the individual.<Callout type="risk" title="Risk">Copper baths can become uneven and difficult to clean.</Callout> Further, it was often found that the floor of the bath got uneven and prevented the entire emptying of the water. Such a bath must also be enclosed. Cast-iron baths were often used in small houses on the score of economy, being finished with stoved enamel paint.<Callout type="warning" title="Warning">Cast-iron baths can be difficult to keep clean.</Callout> Such baths are very difficult to keep clean, and the extra cost of porce- lain enamel, i.e. enamel which has been vitrified, is amply justified, the inside of the bath being then non-absorbent and highly glazed.<Callout type="important" title="Important">Porcelain enamel baths provide better hygiene.</Callout> Porcelain or fireclay baths are satisfactory but open to the objection of cost and are slow in warming up, as the material absorbs so much heat from the water. Marble baths look well, but they are costly to construct, and it is certainly difficult to get a really hot bath in one unless the user is prepared to wait while the marble warms up.<Callout type="risk" title="Risk">Marble baths can be slow to warm and require patience.</Callout> There is a British Standard Specification (B.S. 1189) for porcelain enamelled cast-iron baths, which is now the most commonly used form.<Callout type="tip" title="Tip">Porcelain enamel cast-iron baths offer good hygiene and ease of use.</Callout> Overflow and Waste for Baths. A common form of overflow to a bath is one guarded by a readily removable circular grating, but this is not as good as a type which is immediately accessible.<Callout type="important" title="Important">Accessible overflows are crucial for proper hygiene in baths.</Callout> The form of waste and overflow shown in Fig. 249 is also applied to baths. Fig. 258 shows the application of the tube waste and overflow combined, the tube being attached to a hook.<Callout type="gear" title="Gear">Hooks for tubes ensure easy cleaning and maintenance.</Callout> Such tubes can be of metal or vulcanite and should stand in a recess at the end of the bath, as in the case of lavatory basins. A form of waste outlet sometimes adopted is that shown in Fig. 262, which shows, diagrammatically, a valve outlet, V, controlled by a weighted lever.<Callout type="warning" title="Warning">Valve outlets require regular maintenance to prevent leaks.</Callout> A chain or rod connects the lever with the top of the bath casing where this method is adopted. In some places the water authorities will not allow a bath overflow to be joined up to the waste pipe, but require it to be treated as a warning pipe.<Callout type="important" title="Important">Follow local regulations for proper plumbing installation.</Callout> Fig. 262 shows the arrangement of the pipes which results in such a case, assuming a valve outlet to be used. The sketch is perhaps self-explanatory, but it will be seen that the overflow pipe is discharged over the mouth of the waste pipe of the lead safe under the bath.<Callout type="risk" title="Risk">Improper plumbing can lead to contamination.</Callout> The valve leads into a trap, T, which is provided with a ventilating pipe, V.P. Alternatively the lead safe can be omitted and the overflow will then be taken straight through the external wall to discharge over a garden bed or yard, as shown by the dotted lines.<Callout type="important" title="Important">Properly installed plumbing ensures hygiene.</Callout> One of the problems encountered in dealing with the outlets of baths is that of fixing the trap and its joints in such a way that they are above floor level where they will be accessible, and it is quite usual to find them below floor level.<Callout type="warning" title="Warning">Trap joints must be installed at proper height for maintenance.</Callout> A skilfully designed overflow, plug outlet and trap is shown in Fig. 254. It is the “Cobra” combination fitting made by the A.I. combination of iron-founding firms to fit the baths of any member firm.<Callout type="gear" title="Gear">The Cobra fitting ensures proper hygiene and easy maintenance.</Callout> The Cobra is in coated cast-iron or glass-enamelled iron in two pieces which screw together where indicated. The ends of the overflow and outlet are finished with screwed nipples. These nipples are then fixed from inside the bath with the threaded overflow plate and the outlet flange plate, while a screw-union with tailpiece at the outlet end of trap enables the lead or other form of waste pipe to be connected.
Key Takeaways
- Low-level cisterns offer easier access for maintenance and repairs.
- Ensure proper installation of water waste preventers for efficient operation.
- Choose basins with easily accessible overflows to ensure proper cleaning.
- Weir overflows provide better drainage and are easier to clean.
- Follow local regulations for proper plumbing installation.
Practical Tips
- Use low-level cisterns in your home or survival shelter for easier maintenance and repairs.
- Install water waste preventers correctly to avoid unnecessary water usage and potential noise issues.
- Select lavatory basins with accessible overflows to ensure they can be cleaned properly without difficulty.
- Consider using weir overflows for better drainage and ease of cleaning in your sanitation setup.
- Follow local plumbing regulations when setting up any sanitary fittings, especially if you are in a survival situation.
Warnings & Risks
- Improperly adjusted regulators on valve closets can lead to water wastage.
- Inaccessible overflows can result in hygiene issues and the need for regular cleaning.
- Back-siphonage risks from improperly installed valves can lead to contamination of your water supply.
- Bedroom basins require careful design to prevent contamination, especially if they are not properly sealed.
Modern Application
While many of the specific plumbing technologies discussed in this chapter have evolved significantly since 1920, the principles of proper sanitation and hygiene remain critical. Modern readers can apply these historical techniques by ensuring their systems are accessible for maintenance, using efficient water usage methods like low-level cisterns, and following local regulations to prevent contamination. The knowledge from this chapter still provides valuable insights into maintaining a clean and safe environment in any survival scenario.
Frequently Asked Questions
Q: What is the purpose of a low-level cistern?
A low-level cistern serves as an alternative to high-level tanks, providing easier access for adjustment or repair. It offers a more direct flush with less water wastage and can be used in wash-down or siphonic pans.
Q: Why are accessible overflows important in lavatory basins?
Accessible overflows ensure that the basin can be cleaned properly without difficulty