A ___ check valve is a check valve that prevents backflow through the use of a conical or cylindrical brass disc held in place by a spring.

Natural draft produces greater amounts of draft in the winter than in the summer.

Blowback is the ___ in a boiler that occurs after the safety valve has opened.

___ and waist belts are used to reduce injuries from falling.

If fuel oil is not properly blended, it may stratify in a tank.

The three states of ___ are solid, liquid, and gas.

A check valve is used when fluid flow needs to be restricted or regulated through the valve.

The three states of ___ are solid, liquid, and gas.

If fuel oil is not properly blended, it may stratify in a tank.

High-pressure chillers have an operating pressure greater than ___ psi.