Low pressure drop non return valves screw compressor

[RANGER1]

Has anyone a recommendation for a proven suction check valve on a screw compressor.

Needs to have smallest possible pressure drop across it.

Sizes approx 125-300 mm in size.

Can also be a stop check valve




Thanks Ranger

[Magoo]

Hi Ranger1,
generally have those double plate spring loaded things, but they can generate 1 degree loss at super low suction. Concider a stop check flapper vav straight after the compressor in discharge line between comp and separator.
magoo

[josef]

If there is no escape from the pressure separator to the intake valve is OK.

[Magoo]

Hi Ranger.
how did you get on with check vav.
magoo

[RANGER1]

Magoo,
Just curious really as everyone talks about penalties/efficiency etc etc.
You/I know about discharge check benefits but only a few companies doing it like Bitzer
that I know of.
Have seen a few with I think Grasso stop/checks, but don't know how good they are
compared to Duo checks.

[Magoo]

Hi Ranger,
The duo stop checks are reasonable high pd on suction add the strainer and several degree losses.
I have had a Bitzer discharge check let go, the shaft separated from head [ a friction fit ] and sucked the spring back into screws, not a pretty site.

[Sandro Baptista]

Magoo,
Just curious really as everyone talks about penalties/efficiency etc etc.
You/I know about discharge check benefits but only a few companies doing it like Bitzer
that I know of.
Have seen a few with I think Grasso stop/checks, but don't know how good they are
compared to Duo checks.

Yes. Bitzer screws have a discharge check valve integrated on the screws compressors. Attention: if using ECO you should to use a suction electric valve at the ECO port so preventing the gas flow from the ECO to the main suction.