In my wife's condo she has a front loading washing machine that was installed when the condo was build. The drain hose is taken straight down to a blue pipe, about 3-4" diameter, which emerges through the floor. The hose is sealed into the blue pipe with some foam. Since there is no air gap, this arrangement results in siphoning.  I need to extend the blue pipe up (with reduced diameter) and make a U-bend.  Can anyone tell me the typical waste pipe diameters used in Thailand, and also if its possible to buy some kind of reducer seal to enable insertion of smaller diameter pipe into the large diameter pipe which comes up through the floor.

You can get a 50-40mm reducer, as 40mm would be normal to create a u bend/trap and the stand pipe.

 

Make your own bend  with some 90s and take the pipe up the wall 600mm from the floor.

You can lob the flexi waste from the washer directly into it.

No need to seal it, infact dont!

 

You trap will stop smells, the height and open top will stop siphonage.

 

Dont go less than 40mm....40is for washers and showers, 32 for basin wastes. 50mm when its picking up maybe two wastes...shower and basin.

 

Ah, just seen your floor outlet is 3inch....really?., however yes you can reduce from 4inch to 1inch if you need to

Edited January 16, 20197 yr by eyecatcher

Below photo shows our laundry room standpipe set above the machine water level to prevent siphon. We used 1.5 inch PVC pipe with P-trap to block smells.

In your case the P-trap outlet would connect to your existing drain via suitable reducer arrangement.

 

Thanks guys. Very useful. So it sounds like Thai waste pipe is 32mm and 40mm - same as UK. I'm very familiar with UK plumbing so hopefully this will be straightforward.

2 hours ago, HauptmannUK said:

Thanks guys. Very useful. So it sounds like Thai waste pipe is 32mm and 40mm - same as UK. I'm very familiar with UK plumbing so hopefully this will be straightforward.

Well it probably is, but this being Thailand I would not bet on the size, though there are fittings, reducers, bends, etc for every size though one of the ones you need is probably out of stock. ????

Just remember the hose needs to go up a certain height above the floor like Fruit Trader pictures, then down into the p-trap. The LG techs told me 1-1/2 inch minimum pipe diameter (I prefer 2" and ready made p-traps of this size are common). They also said to make sure to keep the end of the hose above the water line in the p-trap.

 

The discharge hose has to be nominally 1m above the floor.  Most machine hoses have a 180 degree bend at the end for hooking into the PVC pipe.

 

The water is pumped out of the machine there is no valve.  If there is any siphoning it just helps the pump. Siphoning will stop when machine is empty.

Maybe best to just check the manual. Mine says 60cm to 1M above the floor.

 

2 hours ago, canopy said:

Maybe best to just check the manual. Mine says 60cm to 1M above the floor.

 

Yes, I mentioned 600above the floor.

i will also add, that the trap in the above photo appears not to be deep enough...it should be a minimum of 75mm from the bottom of the bend to the bottom of the outlet.

Any less and siphonage will occur

16 hours ago, eyecatcher said:

Yes, I mentioned 600above the floor.

i will also add, that the trap in the above photo appears not to be deep enough...it should be a minimum of 75mm from the bottom of the bend to the bottom of the outlet.

Any less and siphonage will occur

The trap in my photo is a Thai Pipe Co trap with 100mm U section but its not there to prevent siphon. Siphon is prevented by the stand pipe being set at the correct height which in turn creates a siphon break at the machine outlet pipe.

8 minutes ago, Fruit Trader said:

The trap in my photo is a Thai Pipe Co trap with 100mm U section but its not there to prevent siphon. Siphon is prevented by the stand pipe being set at the correct height which in turn creates a siphon break at the machine outlet pipe.

Yes, thats correct, I spent a thousand years with anti vac traps that have the duel purpose of anti siphonage and smell prevention that here back in the dark ages we are making traps ourselves with bends.

My apologies.

Anyone know where I can get a washing machine repaired in Pattaya!