Check valve...?

[The Z'eer]

Looking to buy another 90 ltr Wolf 3HP soon enough. when it’s coupled with the one I already have, I figured fitting a check valve for the airline would be helpful.

It appears these check valves have three ports...

Clarke ½" BSP Non Return Valve - Machine Mart

www.machinemart.co.uk

...I can understand the inlet and outlet, but why the third port? I can’t see the need for this?

Anyone have prior experience? Thanks

 

[Sparky666]

3rd port for pressure switch connection?

 

[wyn]

As said, the third small port is for connection to the pressure switch. You could just blank it off.

 

[rcx132]

I'm not sure that check valve you've linked to is big enough for a 3HP compressor. Machine Mart are surprisingly cheap on check valves, if you call them up and by one as a "spare part" from one of their industrial compressors, I think I paid ~£20.

 

[brightspark]

the valve will be ok on a 14cfm comp

 

[brightspark]

Personally I don't like the MM check valves as they have cheap innards and simply dont last, often the rubbers go and they leak.

the rubber disks went a bit hard on mine and left an indent, i just rubbed them up on some sandpaper and put them back in . been ok for 4 years now

 

[123hotchef]

Looking to buy another 90 ltr Wolf 3HP soon enough. when it’s coupled with the one I already have, I figured fitting a check valve for the airline would be helpful.

It appears these check valves have three ports...

Clarke ½" BSP Non Return Valve - Machine Mart

www.machinemart.co.uk

...I can understand the inlet and outlet, but why the third port? I can’t see the need for this?

Anyone have prior experience? Thanks

what do you want the check valve for?

 

[The Z'eer]

As said, the third small port is for connection to the pressure switch. You could just blank it off.

Thanks for the info I’ll purchase a blanking plug

 

[The Z'eer]

I'm not sure that check valve you've linked to is big enough for a 3HP compressor. Machine Mart are surprisingly cheap on check valves, if you call them up and by one as a "spare part" from one of their industrial compressors, I think I paid ~£20.

Any chance of a link ? The Machine Mart item was featured as a description of a three port check valve.

 

[rcx132]

Any chance of a link ? The Machine Mart item was featured as a description of a three port check valve.

I just measured a spare 3HP valve that happend to be sitting on my desk, it is 1/2" BSP so looks like I stand corrected, the one in your link looks correct for a 3HP compressor.

 

[the snooper]

what do you want the check valve for?

That was my thought, only reason I can see is to stop it back filling the other compressor when you only need to use one

 

[The Z'eer]

what do you want the check valve for?

Combing two 14 CFM compressors.

That was my thought, only reason I can see is to stop it back filling the other compressor when you only need to use one

That’s the idea, although I will incorporate bypass tubing so that I can use both 90 ltr receivers.

 

[Sparky666]

Sorry guys, might be missing something here but wouldn’t it be easier to link outlets and set one pressure switch to cut in before the other, wouldn’t have thought NRV would be required

 

[The Z'eer]

Sorry guys, might be missing something here but wouldn’t it be easier to link outlets and set one pressure switch to cut in before the other, wouldn’t have thought NRV would be required

I’ll have to adjust the pressure switch since the start up of both motors simultaneously will trip a breaker, too much load.

its wise to use a check valve when linking compressors. You want to channel the air to desired source (tool) rather than it refilling the other receiver.

 

[daleyd]

Just use a manual ball valve if you want the flexibility to use either one or the other - I’m with sparky I can’t see the point in a non return valve if your just linking the 2?

 

[The Z'eer]

Just use a manual ball valve if you want the flexibility to use either one or the other - I’m with sparky I can’t see the point in a non return valve if your just linking the 2?

I forgot to mention that I’m not using the regulator/air couplings that were factory fitted to my Wolf 3HP. I take my air directly from the receiver and then use a regulator down the line to throttle to my requirements. Check valves are needed.

Connecting Two Compressors Together - AirCompressorHelp

Connecting two compressors together should be fairly straightforward, and it is, as long as you remember to use a couple of check valves in the plumbing as well. Here is ... Read moreConnecting Two Compressors Together

air-compressor-help.com

 

[Sparky666]

Are the check valves not already fitted from the pump to the receiver?
chances are with the setup unless the pressure switches are adjusted both pumps will likely run at the same time so You would have the mcb tripping anyway.
nice link btw looking at the diagram it shows compressors and check valves which is technically correct but doesn’t show the receiver which I would have where the tool one is shown.
I do get the not wanting to fill both receivers from a single compressor, effectively a common system but each compressor as a stand alone

 

[The Z'eer]

Are the check valves not already fitted from the pump to the receiver?
chances are with the setup unless the pressure switches are adjusted both pumps will likely run at the same time so You would have the mcb tripping anyway.
nice link btw looking at the diagram it shows compressors and check valves which is technically correct but doesn’t show the receiver which I would have where the tool one is shown.

As said, I’ve bypassed the compressor’s factory fitted regulator and thus it’s own check valve as well. My air comes directly out of the compressors receiver, is then linked by a whip hose to a stretch of dog legged copper piping.

I’ll be following the diagram in the link, two check valves with a tee soon after to connect. I have a dedicated circuit for each compressor and necessary breaker too.

 

[daleyd]

I’m still struggling to see the need for check valves. The air isn’t going to leak out of the other compressor, which is what they seem to suggest. The regulator on a compressor doesn’t contain any check valve, that’s between the pump and receiver.

You can of course fit them if you want, and it will work - but it’s an added complication & expense - with both linked together just via plain pipework the system will work just fine, wherever you put your regulator.

 

[brightspark]

That was my thought, only reason I can see is to stop it back filling the other compressor when you only need to use one

and you can just fit a ball valve . that thats all i have