Check Valve for Low Pressure
I am looking for a 12" check valve for Methane at low pressure. Pressure of line is 8" Water column. It is a Biogas installation.
Any idea???
I'm not certain I understand Mike's solution either, but the glimmer I got looks like an elegant solution to a very difficult problem.
FransiscoG,
what are you planning for the check valve to do? Could the task be
accomplished with a compressor-discharge check? Any swing check will
require something on the order of 6" H2O to open, and in a 12" pipe it
is probably more. Your stream doesn't have any extra energy to waste in
operating a check valve unless it is crucial to the operation.
Imagine a lift check valve, the kind you make from barstock. Ports on
either end, coaxial. Communicating holes toward the center, one drilled
up, one drilled down.
At the center, a blind hole drilled from the
top to intersect the lower communicating hole, and a counterbore at the
top, intersecting the upper communicating hole. Ordinarily, you'd put a
lifting poppet and maybe a spring in the counterbore, then cap
it. Forget the poppet. Forget the spring. Just cap the body.
Now, invert it, and fill the counterbore with water.
Gas
flowing in the forward direction of the former lift check valve
depresses the water level and bubbles out to the discharge port.
Gas
flowing in the reverse direction tries to do the same thing, but can't
lift the water in the deep vertical drilled hole, because there isn't
enough pressure to lift the water that far.
Ergo, check valve, with no moving parts other than the gas and the water.
MORE NEWS