Short Answers Only

A. Long Radius ELL - Center to end = 1.5 d, Short Radius ELL - Center to end = 1d

B. Tube is normally small and is based on O.D. Pipe can be very small but often goes up to and beyond 72" diameter. Pipe sizes are based on nominal sizes (Example: 50mm DN = 2" NPS, 100mm DN = 4" NPS, etc)

C. Automatic Girth Welding (AGW) is a circumferential weld done by a machine. Often used on thin wall stainless steel Hygenic piping.

D. Pressure Rating is the same as Flange Class (example: A 150# flange rating is the same as a Class 150 Flange)

E. Re: the use of Polyethylene tape on underground piping. Yes but it depends on the commodity. If it is allowed above ground then you can use it underground.

F. You should contact a paint company for this one.

G. Only you, the Code and your Client can answer this one.

• difference b/w long radius and short radius elbow?

Pressure drop. Long radius elbows give less pressure drop.

• difference b/w tube and pipe?

One finds tube in heat exchangers and pipe virtually everywhere else.

• whts the difference between red lead primer and lead oxide primer ?

If "lead oxide" means "red oxide", then red lead primer is illegal in the UK whereas red oxide isn't.

thanks for yr reply please close this forum now..