Type of pipe fittings?

[misterg]

I need to know the difference between "mechanical" and "flange" pipe fittings with regard to valves made in both cast iron and ductile iron? Would these require gaskets? Thanks.

 

[saxon]

misterg, I take it to mean when you say "mechanical" you mean threaded, socket weld, sanitary joint, tube fit, etc. as opposed to the std. ANSI or DIN type steel flanges. On ANSI class flanges, these come in std. ratings, from 150#, 300#, 400#, 600#, 900#, 1500#, 2500#. The standard facings are, raised face, large male&female, small male&female, large tounge&groove, small tounge&groove, and ring joints. As for flange types, these can be welding neck, slip on welding, lap joint, screwed.

For cast iron flanges, there is class 25#, class 125#, class 250#. These are flat face type flanges, and come as threaded. BTW, these require a full face gasket.

If your bolting up cast or ductile iron valves to the ANSI class raised face flange, be very careful when torqueing the bolts down, normally what happens is the cast or ductile valve flange will crack or snap off if over torqued or the proper bolting tightening pattern is not followed, ruining the valve.

I hope this answers your question.
saxon

 

[LSThill]

saxon (Chemical) ASME DROP CLASS 400#, NOW 300# & 600#

 

[saxon]

isthil, Yeh, but they still exist out in the plants and show up.

saxon