How to Install a Manway into a Small Tank Head

Introduction

Getting a manway out of round can seriously hinder your production schedule and, in some cases, even cause irreparable damage. Today, Jeremy will show you how to install a manway in a small tank head while keeping it round.

1. Add quarter marks to the head to divide it into four equal sections.
2. Tack the head down to the table you are working on or otherwise secure it. This will ensure that the head is held in place during the welding process.
3. After test fitting, you may have to grind some areas back on the head to ensure a good fit for the manway.
4. Lower the manway into the head using a jib hoist or another lifting mechanism and align it with the quarter marks you made earlier.
5. Make sure the manway is sitting level in the head before you tack it into place.
6. Tack the manway to the head. First, tack the manway at the quarter marks and then proceed to close-tack it all the way around.
7. Place a heatsink inside the manway and clamp it into place. A heatsink will ensure the manway does not get out of round during welding. If you do not have a heatsink, you can use a piece of 3/4" thick plywood. Cut the plywood to match the inside of the manway so that it fits snugly inside the manway. This will keep the manway from going out of round during welding, just like the heatsink does.
8. Weld the manway to the head all the way around.
9. After welding the outside of the manway, let the manway air cool completely before cutting the head loose from the table.
10. Flip the head and manway over and weld the inside of the manway to the tank head. Be sure to leave the heatsink or plywood board clamped to the inside of the manway until you have finished welding and the weld area has air-cooled completely. Then, remove the heatsink.