For many busy families, having a fire pit is an ideal outdoor retreat, right in their own backyard. This may look like the beginnings of a fire pit, but in reality, it’s a tank fitting, a flanged and bolted manway that, once installed, will provide personnel access to the interior of the tank.

This is a very large fitting, having an inside diameter of 36”.  The materials are quite heavy and must be moved by overhead crane or forklift.  There are multiple steps involved in making a stainless steel fitting of this nature.

  • Raw materials are purchased:  3/8” plate for the collar (130 pounds), 1-1/4” plate for the blind (manway cover - 492 pounds) and a forging, 46” O.D. x 36” I.D. x 2-1/4” thick (400 pounds) for the flange.
  • Bolting is purchased – (32) 7/8” diameter x 7” long fully threaded studs and (64) nuts.
  • Fabrication of components begins once material arrives.
  • Collar is sheared, rolled, close welded, ground and re-rolled in tank shop.
  • CNC machining to level inside of flange forging and create a bevel for welding.
  • Flange moves to tank shop for welding.
  • Flange is welded to collar, ground, assembly is returned to machine shop.
  • Finish CNC machining of assembly to level top and outside edges; also drill 32 bolt holes.
  • Blind (manway cover) is waterjet cut, machined and 32 bolt holes are drilled.
  • Two handles are formed from 1/2” diameter round bar, welded to blind and ground.

The process takes several days from start to finish since the components must move through various departments in the shop.  Once the assembly is complete, it will be held in a staging area until the tank is ready for the manway to be installed.

Visit our photo gallery to see a 15,000 tank outfitted with a similar, but smaller, flanged and bolted  manway:

36" fitting for a flanged and bolted manway 

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