Considering he'll be using propane for his first unit,
Here's the zippo testing way from my parts you'll need.
A zippo is like a butane lighter if you didn't know.
You fill your unit static charge to 50 psi, then take the butane lighter and light it and move it around by the joints. This will tell if theres a leak by a small flame coming from the pipe.
It works really well, dont trust your pressure gauges as oil will absorb some of the propane. To positive pressure test, braze an access valve to both discharge and suction of your vacuum pump (rotary compressor in his case). Remove the valve peice from the suction one and hook your charging hose (yellow) to the discharge. Open all the valves and turn on the rotary, fill your single stage to around 250 psi and then do the soapy water test.
Here's the zippo testing way from my parts you'll need.
A zippo is like a butane lighter if you didn't know.
You fill your unit static charge to 50 psi, then take the butane lighter and light it and move it around by the joints. This will tell if theres a leak by a small flame coming from the pipe.

It works really well, dont trust your pressure gauges as oil will absorb some of the propane. To positive pressure test, braze an access valve to both discharge and suction of your vacuum pump (rotary compressor in his case). Remove the valve peice from the suction one and hook your charging hose (yellow) to the discharge. Open all the valves and turn on the rotary, fill your single stage to around 250 psi and then do the soapy water test.