Presentation on Trap Loss PLUMBING Presentation on Trap Loss

Trap Loss At the end of this session you should be able to : Explain what is meant by trap seal loss

Why does Trap seal loss occur ? Trap Loss Why does Trap seal loss occur ? Trap seal loss occurs when the seal of the trap is lost as a result of poor practice and by not following the regulations with regard to sanitation pipework installation.

There are three main causes of loss of trap seal: Trap Loss There are three main causes of loss of trap seal: Self siphonage Induced siphonage Compression Each one of these is the result of poor installation work

Induced Siphonage Caused by appliances connecting into a common waste discharge pipe. This arrangement is not acceptable on primary ventilated stack.

Self Siphonage Most common in washbasins and steep sided appliances. Ensuring the waste pipe is at the correct length and fall would avoid this problem

Compression Usually caused by discharging W.C. higher than the lowest waste connection. Use large radius bend at base of stack (min 200mm) Min 450mm between invert of the drain and lowest branch waste pipe.

Trap Loss prevention Anti siphon trap

Maximum pipe runs Observe these maximum pipe lengths and you shouldn’t have a problem. Loss of the trap seal can also pose a health hazard. Appliances Dia (mm) Min.trap seal depth (mm) Max. length of pipe (m) Pipe Gradient inDeg ° Max Bends No. Max drop (H) m Washbasin or bidet 32mm 75mm 1.7m 2.2 40mm 3.0m 1.8 to 4.4 2 Bath or shower 50mm No limit 1.8 to 9.0 1.5 Bowl urinal 1.8 to 1.9 Trough urinal Kitchen sink Dishwater or washing machine 1.8 to 1.4 W.C. 110mm 1.8 min

Session Summary We discussed what the causes of trap loss are. Looked at each of the causes of trap loss. How to rectify the problem of trap loss.