VAPER (Vent Audit for Packing Emission Reduction)
A 2017 paper from Colorado State University concluded that 52% of compressor packing vent emissions come from 5% of machines.
Due to the changing regulatory environment, methane leaks are now on everyone’s radar, elevating the importance of controlling compressor rod packing case emissions. VAPER allows operators to quantify and track these losses, so that intelligent control methods can be deployed.
Measurement of rod packing leakage does not require custody transfer precision, and it needs to be inexpensive and simple. The solution is in the technique employed by the “Orifice Well Tester”, which was used for decades to measure gas being vented to atmosphere.
Due to the changing regulatory environment, methane leaks are now on everyone’s radar, elevating the importance of controlling compressor rod packing case emissions. VAPER allows operators to quantify and track these losses, so that intelligent control methods can be deployed.
Measurement of rod packing leakage does not require custody transfer precision, and it needs to be inexpensive and simple. The solution is in the technique employed by the “Orifice Well Tester”, which was used for decades to measure gas being vented to atmosphere.
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The VAPER kit uses a 1/8” orifice nipple, which does not cause backpressure on the Ariel compressor frame when the packing is in good condition, but a packing case leaking at Ariel’s suggested alarm point of 1.7 to 3.4 CFM would create 1 to 5 psi of backpressure. Since the frame is rated for 25 psi, this measurement system is acceptable.
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Measuring Leak Rate with VAPER
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In order to measure the leakage rate, the location where the packing case gas exits the compressor skid must be identified. A 30 psi pressure gauge, a precision 1/4” x 1/8” orifice nipple, 1/4” 3 way ball valve, and several 1/4" fittings are installed to allow unrestricted flow during normal conditions.
STEP 1: Measure the unrestricted flow pressure STEP 2: Slowly swap the 3 way ball valve position, routing the leaking gas through the orifice STEP 3: Read the pressure STEP 4: Follow the App instructions to obtain rate 
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