Molded in Marelon vent: Provides superior corrosion resistance for long-lasting performance
One-way duckbill valve: Ensures the cap seals properly even with particulate matter in fluids
Compatible with 3/4 and 1 1/2 inch Forespar vented loops: Offers versatility for different system sizes
Simple manual operation: Allows easy installation and maintenance
Summarized by Shop
Forespar 903002 MF841 Replacement Cap Assembly for Vented Loop p/n 903002
This same cap is used on both the 3/4" and the 1-1/2" version of Forespar's vented loops.
Features: This simple valve system when incorporated in the top of a vented loop allows air to enter the line when it is not in use Then it effectively seals as water or other flu