When the pressure in a boiler exceeds the maximum allowable working pressure (MAWP), the ___ valve opens and discharges hot water to a drain bottom blowdown vent safety relief fixing defects Question at position 31 31 Multiple Choice 4 points Question at position 31 A(n) ___ is commonly used to locate small leaks in potable water supply and distribution piping. smoke chamber ultrasonic leak detector acoustic leak detector manometer Question at position 32 32 Multiple Choice 4 points Question at position 32 ___ is commonly used for water service piping, cold and hot water distribution, and hydronic (radiant) heating systems. Cross-linked polyethylene (PEX) Polyethylene(PE) Polyvinyl chloride (PVC) Chlorinated polyvinyl chloride (CPVC) Question at position 33 33 Multiple Choice 4 points Question at position 33 A(n) ___ valve is a four-way directional valve that reverses the flow of refrigerant through a heat pump system expansion reversing discharge pilot