Double Restraint of DI Piping

For underground water mains (ductile iron at 350 psi working pressure), generally 12 to 24 inch diameter, a client's specifications appears to require restrained joints AND thrust blocks, anchors, or tie-rods. What I would describe as double restraint. My experience has been restrained joints OR thrust blocks, anchors or tie-rods. We are scheduled to discuss this with the client, and I am interested to know whether others have provided double restraint design and for what reasons? To be doubly sure of restraint when cost is not a primary concern?

Ken A. Nisly-Nagele, P.E.

Project Engineer, Mechanical

Applied Engineering Services, Inc.

7999 Knue Road

Indianapolis, IN 46250

317-585-8920

[Non-text portions of this message have been removed] Received on Fri Oct 14 11:02:00 2005