3/4 bsp thread sealing - Kranzle inlet

[Chipstick]

I’m plumbing in a Kranzle pressure washer with stainless hoses and fittings etc rather than the usual hosepipe and I notice that the 3/4” bsp female thread on the water inlet has flats on the top and bottom.



I’m looking to connect a 90 degree elbow which I can run a stainless hose from.



The 90 degree elbow would ordinarily be sealed with ptfe tape but the flats on the Kranzle fitting means I (think I) need a connection between with a rubber washer.

I have been looking for a solution and a 3/4” female to male tap extension piece appears to be a solution but I can’t see any suggestions that the fitting would take a rubber washer. The best image I can find shows a slight seat where a washer could sit. Are these designed for a rubber washer?




Or is there a better way? I know I could buy quick connects etc and bring it out that way but personally don’t see the benefit in a quick release for the inlet as it will stay assembled.

[biggiles]

I agree it would need a face washer to seal the join, not PTFE.

Can you do it with blue pipe instead of stainless? Much easier, lots of connectors available. 20mm or 25mm should be ample.

[GasEngineer]

A water soften hose should do it.

eg:

https://www.amazon.co.uk/Water-Softener-Installati...

[Chipstick]

Trouble is I already have 99% the parts including the stainless hose etc but annoyingly didn't think to remove the existing garden hose adapter from the machine to notice the flat areas on the thread.

I also wanted to use the stainless elbow rather than the angled washing machine hose type purely for aesthetics. I'll stick my head in a plumbers merchants and pick up one of those adapters and see if it seals.

[Inbox]

What about the steel braided flexi pipes used for bath taps, etc available from screwfix and others?

[biggiles]

It's a smart elbow (I thought it was ductile iron until I saw the 316 stamp).

Will the Kranzle be connected by rigid pipe to the wall/inlet? There is some vibration of the pressure washer, it may need some flexibility in your piping.

[Belle427]

A flexible hose as suggested would be better, easy to disconnect too in the future as if it's all solid pipework from start to finish you would need to take it all apart.

[dhutch]

Yeah, gotta be flexible for the last foot as the pump will move and vibrate.

As as said, the connection is designed to be face sealing, as it would with a garden hose adapter.

[andy43]

As above I reckon a 3/4” flexi tap connector with a flat washer, then you can plumb the other 15 or 22 end in brass.

[ollie plymsoles]

A 3/4 bent tap connector should do it. Can get the other end in 15mm or 22mm to adapt to the hose.

[ecs]

As others have said, a flexi hose would be good due to vibration. However if you ever find yourself needing to seal threads on another application then this stuff is very good:

https://www.screwfix.com/p/flomasta-pipe-thread-se...

I usually use it for things like garden taps in replacement of PTFE tape.

[Chipstick]

Sorry I should have said there is a flexi coming from the elbow to the water supply. Dry fit mockup:

dhutch said:

Yeah, gotta be flexible for the last foot as the pump will move and vibrate.

It certainly vibrates and moves - it fell 5 feet to the ground the first time I used it as I hadn’t mounted it to the shelf. Fortunately the link hose to my reel was just shy of 5 feet and broke the fall slightly. It’s remarkably still in one piece!

So I went around a few plumbers merchants and none carried the adapter I wanted there and then. I decided on reflection if I’m going to have to wait a couple of days for an online order I may as well go down the quick connect coupler route for a few quid more.

[Chipstick]

andy43 said:

As above I reckon a 3/4 flexi tap connector with a flat washer, then you can plumb the other 15 or 22 end in brass.

Good call, this is exactly how I intended to do it, continuing on to 15mm copper pipe.



Although since all this searching around I have realised I really want a ball valve there between the flexi hose and copper pipe so I can isolate the machine.

Currently thinking 3/4” female to female ball valve with a 3/4” male to male nipple to join to my flexi or flip the flexi around and change the stainless elbow to a male thread.

It’s a game eh!

[smifffymoto]

Fernox LS-X sealant is your friend in these situations.

[dhutch]

smifffymoto said:

Fernox LS-X sealant is your friend in these situations.

No, using a flex hose that seals on the face is you friend in this situation.

[smifffymoto]

dhutch said:

smifffymoto said:

Fernox LS-X sealant is your friend in these situations.

No, using a flex hose that seals on the face is you friend in this situation.

Anything that stops a drip or leak is your friend.

[netherfield]

Could have used a washing machine hose connected to the machine, the other end to a shut off valve as used again when plumbing in a washing machine.

[JoshSm]

netherfield said:

Could have used a washing machine hose connected to the machine, the other end to a shut off valve as used again when plumbing in a washing machine.

That was my thought. You can buy stainless braided applicance hoses with a right angle fitting off the shelf.

[TA14]

netherfield said:

Could have used a washing machine hose connected to the machine, the other end to a shut off valve as used again when plumbing in a washing machine.

Good call.

[dhutch]

netherfield said:

Could have used a washing machine hose connected to the machine.

Yep. Its just a long 3/4bsp flexi with a 90deg on one end.