Expansion vessel hose

[Matt0029]

Do many merchants sell 1 meter long 3/4 male to 3/4 female. The 3/4 male screws in to the composite valve and the other end the expansion vessel. I presume came supplied with the composite valve. The flexi is leaking.

 

[Deleted member 120897]

Is this for a boiler? Usually they’re available as a spare.

 

[ShaunCorbs]

I hard pipe them

Might be easier to use a male iron and a short bit of copper and a stnd 3/4 22mm flexi ?

 

[Matt0029]

I hard pipe them

Might be easier to use a male iron and a short bit of copper and a stnd 3/4 22mm flexi ?

Screw that out and hard pipe it?

 

[ShaunCorbs]

You can do as it’s best but if you want you can use a flex

 

[Matt0029]

You can do as it’s best but if you want you can use a flex

Thanks it maybe hard to get the correct flexi. May solid pipe

 

[Matt0029]

It's a 250litre cylinder. The expansion vessel is only only 18 litres. I'm correct in saying that is under sized and should be a 25 litre expansion? I have fit 18 litre ones on 150 litre cylinders.

 

[ShaunCorbs]

Depends on mi spec but yes normally 24l /25l on 210 up

 

[Matt0029]

Thanks the pressure relief is dripping I'm wondering if the vessel possibly being under sized is the course.

 

[John.g]

If the precharge & filling pressures are correctly set then a 18L EV will have no problem in taking up the expansion from a 250L cylinder heated to 65C.
Precharge/filling/Final (24L EV final pressure in brackets)
1.8/2.0/3.12bar (2.77bar)
2.3/2.5/3.79bar (3.39bar)
2.8/3.0/4.46bar (4.0bar)

Check air end pressure, this (precharge) would have to fall to ~ 0.7bar to cause the expansion valve to lift at 6bar. If the expansion valve is only dripping in the morning then the PRV may be passing overnight, a (filling) pressure of ~ 3.5bar will result in a final pressure of 6bar when the full 250L is heated to 65C.