Sierra 18-4456 Exhaust Protector Valve - Replaces GLM 89240, Mallory 9-44000, Mercruiser 34765A2/34765A1

The Sierra 18-4456 Exhaust Protector Valve is a lift check valve designed to protect an inboard or sterndrive engine's exhaust system from water intrusion. Machined from metal for durability in the marine engine bay, the valve uses 3 inch NPT (National Pipe Tapered) threaded connections and features two ports for inline installation in the exhaust path. Its compact 0.39 x 0.39 x 0.39 inch body allows it to fit into the same mounting space as the original equipment valve it replaces.

Sierra manufactures this valve to meet or exceed original equipment quality, making it a direct functional replacement for the OEM valves listed below. The Sierra 18-4456 is built for reliable, long-term service protecting the engine from backflow of water through the exhaust system.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-4456
• Item Type: Exhaust Protector Valve
• Valve Type: Lift Check Valve
• Material: Metal
• Exterior Finish: Machined
• Thread Type: NPT
• Thread Size: 3 inches
• Inlet Connection Size: 3 inches
• Inlet Connection Type: National Pipe Tapered
• Number of Ports: 2
• Item Dimensions: 0.39 x 0.39 x 0.39 inches
• Weight: 0.43 pounds
• UPC: 030999621856

Replaces (OEM)

• GLM 89240
• Mallory 9-44000
• Mercruiser 34765A2
• Mercruiser 34765A1

Frequently Asked Questions

What is the Sierra 18-4456 Exhaust Protector Valve used for? It is a lift check valve installed in an inboard or sterndrive exhaust system to prevent water from flowing back into the engine, protecting it from water intrusion damage.

What OEM part numbers does the Sierra 18-4456 replace? The Sierra 18-4456 is interchangeable with GLM 89240, Mallory 9-44000, and Mercruiser 34765A2 and 34765A1.

Is the Sierra 18-4456 a genuine OEM part or an aftermarket replacement? It is a Sierra aftermarket replacement valve engineered to meet or exceed the quality of the original equipment part it replaces, including the Mercruiser 34765A2 and 34765A1 valves.

What are the dimensions of the Sierra 18-4456 valve? The valve measures 0.39 x 0.39 x 0.39 inches, a compact size that fits the same mounting space as the original equipment exhaust protector valve.

What material is the Sierra 18-4456 Exhaust Protector Valve made from? The 18-4456 is made from machined metal, giving it durability for use in a marine engine's exhaust system.

What thread size and type does the Sierra 18-4456 use? It uses a 3 inch NPT (National Pipe Tapered) threaded connection at the inlet.

How many ports does the Sierra 18-4456 valve have? The Sierra 18-4456 Exhaust Protector Valve has two ports.

What type of valve is the Sierra 18-4456? It is a lift check valve, which allows exhaust flow in one direction while blocking water backflow.

How much does the Sierra 18-4456 weigh? The Sierra 18-4456 Exhaust Protector Valve weighs 0.43 pounds.

Does the Sierra 18-4456 fit the same applications as the Mercruiser 34765A2 valve? Yes, the Sierra 18-4456 is a direct interchange for the Mercruiser 34765A2 and 34765A1 exhaust protector valves, as well as the GLM 89240 and Mallory 9-44000 equivalents.

What finish does the Sierra 18-4456 have? The valve has a machined metal finish.