Dimensions in illustration: A = 3 in. NPT (76mm), B = 1 3/4 in. (45mm), C = 4 1/4 in. (108mm), D = 5 1/2 in. (140mm)
How to Install a Bulkhead Fitting.
Remove the sealing gasket and use it as a pattern to cut the hole.
Place the gasket over the area where the bulkhead will be installed and mark on the inside of the gasket. When cutting the hole in hard plastic or fiberglass it is best to use a hole saw. Use a breakaway type knife or other small blade sharp knife to cut a clean hole when installing the bulkhead in a flexible pond liner.
The bulkhead can be installed with the nut on the inside or the outside of the liner.
Apply a bead of silicone sealant or lap sealant to the gasket and place this on the wet side of the installation. The sealant will act as a lubricant to keep the liner from bunching up and also help to create a watertight seal.
Tighten the nut to the point that the gasket is crushed against the liner. Install a male adapter to attach your plumbing to the bulkhead. You can then glue pipe into this adapter to finish the installation.
We recommend the use of flexible PVC pipe to allow some movement to relieve any stress that could be exerted on the bulkhead fitting.