Illustrated Encyclopedia of Building Services

David Kut

• Publisher: Routledge
• Year: 2013
• eBook ISBN: 9781135274412
• Edition: 1
• Topic: Architecture
• Subtopic: Architecture Methods & Materials

This book explains over 3,000 terms (over 200,000 words) and contains over 200 professionally drawn line illustrations. This practical handbook is intended for day to day use as a reference or as a source of enlightenment for anyone associated with the building and construction industry. It also provides comprehensive practical explanations of the many terms listed, giving guidance, examples of use and, in certain cases, cautionary remarks concerning aspects of the applications.

SR system A sewer renovation method (by Rice–Hayward) which uses a helically wound PVC strip to form a liner. See uPVC spiral relining.

sacrificial anode That electrode of an electrolytic or corrosion protection system at which oxidation occurs and the material of the anode goes into solution.

saddle [Fig. 192] An inverted U-form steel or plastic clip to secure a cable in position. Different types of saddle are available to suit the application. A space bar saddle keeps the cable some distance off the walls and allows cleaning and painting of the back of the cable.

[Fig. 192] Saddles and crampet for fixing conduit

safety cut-out A device which switches off the power source to a system or process when dangerous conditions are about to arise.

safety factor A margin of performance or of structural strength built into a design to allow for exceptional operational factors which are not known at the design stage, e.g. excessively heavy snow loading on a roof, an earthquake, or accidental overloading.

safety valve A valve that automatically discharges fluid to atmosphere so as to prevent a predetermined safe pressure being exceeded. It is generally used for compressible fluids such as steam, air and other gases which require the speedy relief of overpressure and is available in different modes and types to suit particular applications. See also relief valve.

safety valve, pilot-operated See pilot-operated safety valve.

safety valve, pop type A safety valve used with air receivers, that is spring-loaded with a square valve seating which gives a tight shut off. It is usually complete with easing lever, adjusting screw and locknut, valve guard washer and shims for adjusting the clearance of the guard washer.

safety valve spring-loaded A safety valve in which the valve seat is held shut by the tension of a spring. Usually the pressure setting of the valve can be adjusted by changing the tension of the spring.

saline Containing salt, especially the salts of alkaline metals and magnesium. A saline solution is a solution of salts in water.

salinometer A form of hydrometer used for determining the concentration of salt solutions by measuring their density.

sander dust Finely powdered wood-waste collected off wood finishing or sanding machines. It is highly explosive, being spontaneously ignitable at about 400°C. It is usually collected in a separate dust collection system and cannot be safely incinerated in common types of incinerators without the risk of a dangerous explosion.

sand filter, pressure filter [Fig. 193] A filter contained within a steel pressure vessel. It can operate under pressure if the hydraulic conditions within the connected system require it to do so. It receives unfilterered water and after passage over the filter bed, discharges the filtered water to the process.

[Fig. 193] Cut-away view of an industrial sand filter

sanitary installation gradient This must be adequate to promote self-cleansing of the internal bore.

sanitary plumbing, modified single-stack system [Figs 194, 195] A system that provides ventilating pipework extended to atmosphere or connected to a ventilating stack and is installed where the disposition of some appliances on a branch discharge pipe could cause loss of their trap seals. The ventilating stack need not be connected directly to the discharge stack and can be smaller in diameter than that required for a ventilated stack system.

[Fig. 194] Sanitation: modified single stack system with single appliances

[Fig. 195] Sanitation: modified single stack system with multiple appliances

sanitary plumbing, single-stack system [Figs 196, 197] A system used in situations where it is practicable for the discharge stack to be installed in close proximity to the sanitary appliances, but only in cases where the diameter of the discharge stack is sufficiently large to limit pressure fluctuations without the need for a ventilating stack. All the sanitary appliances, including the WCs, are connected only to the discharge stack, no other stack being provided.

[Fig. 196] Sanitation: single stack with single appliances

[Fig. 197] Sanitation: multiple appliances

sanitary plumbing, stub ducts Ducts used in single-storey buildings and on the ground floor of taller buildings where positive pressures may cause problems if the sanitary appliance is connected to the main discharge stack. A short discharge stack of 100 mm diameter with the top closed, preferably with an access fitting, may be used to connect each of the sanitary appliances (bath, shower, wash-basin, sink, washing machine and WC) directly to drain, providing that the depth to the drain invert level does not exceed 1.5 m from the crown of the WC trap and 2 m to the centre of the topmost connection to the stub stack. Drains which receive the connections of a number of such stub stacks must be adequately ventilated at the upstream end.

sanitary plumbing, ventilated stack system [Figs 198, 199, 200, 201] A system used in situations where the close grouping of sanitary appliances makes it practicable to install branch discharge pipes without also providing branch ventilating pipes. However, a separate ventilating stack is required. Trap seals are safeguarded by extending the two stacks to atmosphere and by cross-connecting the ventilating stack to the discharge stack. Single WCs or ranges of WCs are connected to the ventilating stack off the top of the horizontal connection.

[Fig. 198] Sanitation: ventilated stack system with single appliances

[Fig. 199] Sanitation: ventilated stack system with multiple appliances

[Fig. 200] Sanitation: ventilated system with single appliances

[Fig. 201] Sanitation: ventilated system with multiple appliances

sanitary plumbing, ventilated system A system used in situations where there are a large number of sanitary appliances installed in ranges or where these appliances are widely dispersed and close proximity to stacks is impracticable. The system comprises two separate stacks: a discharge stack and a ventilating stack. Trap seals are safeguarded from loss of water by extending each stack to atmosphere and, excepting ranges of WCs, providing individual branch ventilating pipes. Each WC, or range of WCs, is connected off the top of the horizontal WC connection into the ventilating stack.

sanitary stack, wind effect Wind blowing across roofs can induce pressure fluctuations in the vicinity of parapets and corners of a building. Discharge or ventilation stacks which terminate in such locations can become subject to unacceptable pressure fluctuations in the discharge system. The designer must exercise great care in the location of the stack terminals to avoid possible adverse wind effects.

sanitary ware A term that encompasses all the models, types and varieties of sanitary fittings, e.g. baths, basins, bidets, and sinks on a project.

sanitation, relief pipe An additional ventilating pipe connected to a soil or waste pipe at any particular point where excessive pressure fluctuation can be anticipated.

Sankey diagram [Fig. 202] A heat flow diagram which illustrates the destinations of the available heat by horizontal bands of appropriate widths.

[Fig. 202] Typical sankey diagram

saturated air Air that contains all the water vapour it can absorb at the prevailing temperature.

saturated steam Steam which has taken up its full capacity of latent heat and contains neither moisture nor suspended unevaporated water. It is also defined as dry saturated steam.

saturation The state of a substance in which it has absorbed as much of another substance as it can contain without spillage.

scale A solid encrustation derived from impurities in water. Accumulation of scale inhibits heat transfer and the free flow of fluid.

scale pocket An assembly comprising a small length of vertical pipe, a tee fitting and a drain plug, commonly fitted into a pipeline ahead of stream traps, etc., to trap and collect dirt, scale and sludge.

schedule of rates A schedule prepared by the contractor on request indicating the itemized costs per unit of pipe, fitting, etc. for use in the subsequent agreed costing of the completed works.

Scottish Power one of two electricity supply companies in Scotland.

screened cable Cable that incorporates a protective shield which isolates it from undesirable electric or magnetic influences.

screen, electric A shield which isolates electrical equipment, circuits, etc. from the undesirable effects which could be caused by external electric or magnetic fields. It similarly applies to screened cable.

screw compressor A compressor in which two meshing helical-shaped screws rotate and compress the gas as the volume between the screws decreases towards the discharge end. It is generally used in the larger size ranges of positive displacement compressors, in capacities up to about 3000 kW. It is considered reliable, efficient and low-cost equipment.

screwed joint A method of joining pipes by screwing one component into another and securing tightness of soldering, compression or cementing.

screw-down and stop check valve A valve that incorporates a mechanism that can hold the disc in the closed position independently of flow or, alternatively, can restrict the lift of the disc. It differs from the globe valve only in that the disc is not attached to the valve stem. Optionally, it may embody a dashpot and a piston to cushion the valve movement.

screw-down stop valve A valve in which the disc is lifted from and lowered on to the body seat b...

Table of contents

• Cover
• Halftitle
• Title
• Copyright
• Contents
• Acknowledgements
• A
• B
• C
• D
• E
• F
• G
• H
• I
• J
• K
• L
• M
• N
• O
• P
• Q
• R
• S
• T
• U
• V
• W
• Y
• Z