What is a Low-Pressure Drain?
This question is usually asked by several of our producers and farm hands when told they are missing the low-pressure drain (LPD) off their wells, which is required safety equipment to prevent contamination of a well and ultimately the aquifer. This little piece of equipment is required as per the Texas Water Code 36 and further required as per the NPGCD Rules Chapter 4, Rule 4.5.1.F. The purpose of the LPD is to drain off any leakage of water and injection chemicals from the check valve, upon securing the well and/or loss of power to the well—see the illustration of the typical check valve with the low-pressure drain shown below.
Once this is explained, it is usually called something else by the producers and farm hands as a back-flow preventer, or freeze drain. The LPD maybe called by a more colorful name when it quits working properly on the well. This failure or leakage is usually caused by debris and sand build up in the LPD valve seating surface. So, when the well is shut down for an extended period, an oil change, or just maintenance; pull the valve out and open the check valve via the inspection port and clean out the debris and flush out the buildup before placing the well back on-line.
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