The internal construction is designed to improve ease of assembly. The moulded cores simply slide over the centre tube, followed by spacer plates (if applicable). The outlet plate is fastened to the assembly by a wing screw. With the addition of a spring, the resulting assembly is easy to install and remove.
The seal gasket prevents solid contaminants from bypassing the filter. The assembly is held tight against the gasket by a spring. O-rings are used with the secondary filter to provide a tight seal.
The internal parts are plated steel – no plastic parts.
Heavy steel shells provide high bursting strength and are listed by Underwriters Laboratories Inc. The shell exterior uses an epoxy powder coating to prevent corrosion even under the most adverse conditions.