Why is a thermal relief kit needed with a diaphragm pump?
Thermal expansion usually arises from a cooler fluid running from a tank or barrel to a overhead reel (i.e.: oil in the pump room @ 60F – going 100ft. to overhead reel @ 80F). The difference in temperature causes the oil to expand ( 1 degree rise in temperature causes a 45 PSI increase in oil pressure in the closed system). This can cause damage to piping, reels, and meters. A thermal relief kit installed @ the pump usually alleviates this problem.
