Water introduced into a boiler during operation. It includes make-up and return condensate.
Feeler gauge
Also called a thickness gauge, this series of precision thickness, metal blades is used for measuring small gaps, with each blade being marked with the thickness in thousandths of an inch.
Feet per minute (fpm)
This measurement of the velocity of air or other mediums is used in calculating pump capacity or for HVAC systems, etc.
Felt
(1) Fabric whose fibers are worked together by pressure, heat, chemical action, etc. instead of being woven or knitted. (2) Felt, saturated with an asphalt compound, which is used under roof shingles or flashing for water resistance.
Felt machine
A machine that will install bitumen and felt at the same time.
Felt paper
Papers, sometimes tar-impregnated, used on roofs and sidewalls to give protection against dampness and leaks.
Felt paper, 15-pound
Felt papers
Fabric made of different fibers, such as glass-fiber felts or asbestos fiber felts. Female Plumbing term for the pipe or fitting that receives the end of a pipe or fitting, called the male.
Female fitting
A fitting that receives a pipe or fitting. A fitting into which another fitting is inserted.
