150 lb Pipe Rating

"150 lbs" is the old terminology for a Flange rating designation.

The proper current terminology would be "Class 150"

This type of designation only applies to Pipe Flange Ratings

The Flange rating scale uses both a pressure scale and a temperature scale.

The pressure allowed will be higher if the temperature is low or the pressure will be lower if the temperature is higher.

Go to this web site to see an example of a Flange Rating Table matrix

http://www.weldbend.com/Technical%20Data/Pressure%20Temperature%20Ratings%20For%20Flanges/prestemprateforflng.htm

Pipe Rating is based on the wall thickness and uses the terminology such as "Schedule" as in Sch 40, Sch. 80 or Sch 160.

or

"Weight" as in XH (Extra Heavy), XXH (Double Extra Heavy)

Go to this web site to see a chart of the standard commercially available pipe sizes and wall thicknesses.

http://www.maselmon.com/Content.aspx?ContentID=24

You must do calculations (defined in the appropriate Code) to determine the minimum required wall thickness for your application.

vessels (bulbous pipe) used to be tested above ground using compressed air. Now they are tested under water.

Your residential water heater for example is tested and certified to 150 psi. (on rating plate) and the incoming wat press. is usually 50 to 60 lbs. and safety relief valves are rated at 150 lbs max, and also a BTU rating.

H T H cheers