3 Inch 304 Stainless Steel Spring Assisted Exhaust Rain Cap for Vertical Stack Pipe and Muffler Rain Cap Flap

This 304 Stainless Steel Exhaust Rain Cap — also known as a Stainless Steel Exhaust Flapper Rain Cap or Muffler Rain Cap Flap — is engineered for vertical exhaust stacks on diesel generators, trucks, and tractors.

• Premium SUS304 stainless steel construction for long-lasting defense against rust and salt spray corrosion.
• Self-acting gravity flapper structure responds to exhaust airflow for unobstructed venting.
• Automatically seals after shutdown to block rain, snow, debris, and critter intrusion.
• Directly supplied by the source factory at a discounted price.

The spring loaded exhaust rain cap is chosen whenever the engine spends long periods at idle or the stack cannot be guaranteed vertical. It is commonly used on:

1. Standby and prime power generator sets running long low-load periods.
2. Forklifts and yard equipment where the stack leans after impact.
3. Marine auxiliary engines with short, near-horizontal stack runs.
4. Boiler and heater flues that must stay sealed when the burner is off.

Every unit is cycled ten times on the test bench and the closing gap is measured before packing. A cycle-test summary is available for tender packages. Lead time is 7 to 25 days, and mixed cartons of 2.5, 3, and 4 inch sizes are available for trial orders.