Boiler Piping, Valves, and Fittings Code Review

Flashcards covering requirements for blowoff piping, safety valves, pressure-reducing valves, valve designs, threaded joint limitations, and material standards from the lecture notes.

When are outside screw and yoke valve designs required for piping systems?

NPS 3” & larger for pressures over$600\,\text{psi}$

What is the code definition of a Slow-opening valve?

A valve that requires at least five full $360^\circ$ turns

What are the sizing and material requirements for valve bypasses?

bypasses shall be at least 3/4” & Schedule 80 seamless pipe.

What radius is required for sweep bends in boiler blowoff piping between the boiler and blowoff tank?

Pipe connections must use sweep bends having a radius of three times the diameter of the pipe.

What pressure and temperature conditions must boiler blowoff discharge meet prior to entering a sanitary sewer system?

Blowoff must pass through a blowoff tank or apparatus that reduces the pressure to not more than 5 PSIG and the temperature to not more than $140^\circ\text{F}$.

What piping material requirements apply to blowoff systems when pressure exceeds $100\,\text{psig}$?

Pipe and fittings shall be steel with a thickness not less than Schedule 80 pipe. Galvanized pipe or fittings shall not be used.

What valve arrangements are mandated for boiler blowoff when pressure exceeds 100 PSIG?

Two blowoff valves shall be used, with at least one valve being of the slow-opening type. If a quick-opening valve is used, it must be located nearest the boiler.

What are the required installation clearance distances for blowoff tanks?

Blowoff tanks must be installed with a space of not less than $18\,\text{inches}$ between the tank and wall, and not less than $12\,\text{inches}$ between the tank and the floor.

What is mandatory regarding pressure gage installation on pressure-reducing valves?

It is mandatory that a pressure gage be installed on the low-pressure side of a reducing valve, and on the low-pressure side of each reducing valve when two or more are installed in series.

At what temperature limit are threaded pipe joints completely prohibited?

Threaded joints are prohibited above $925^\circ\text{F}$.