Re: Cast iron pump nozzle with RF flange

On Jan 23, 2008, at 1:40 AM, sviswan@technip.com wrote:

> How does the use of a low strength bolt ensure that the bolt load
> does not
> exceed so much as to cause it to break (if the RF were used). I
> suppose
> this has to be limited by the limiting the torque used for the bolt
> up.

The most important thing to remember is to be damn sure the joint is assembled with due care to avoid overtightening or the need to jack the flange into place with the bolting. Cast iron won't yield under high loading, so can't depend on a little plastic deformation to make up for misalignment. I don't much like using cast iron in pressure vessel work, especially fatigue or fracture critical designs, although other people don't have issues. It's been successfully used in water distribution systems and a lot of other areas for dogs years, but the possibility of abuse makes me nervous.

Christopher Wright P.E. |"They couldn't hit an elephant at chrisw@skypoint.com | this distance" (last words of Gen.

.......................................| John Sedgwick, Spotsylvania