Roper Pump N3-200 Relief Valve Faceplate Assembly for 3611 to 4722
The Roper N3-200 is the relief valve faceplate assembly with bronze bearings for 3600 Series pumps in the 11, 17 and 22 sizes, spanning the 3611 through 4722 range. It does everything the plain faceplate does, carrying two of the four gear bearings and locating to the case on hardened dowel pins, and adds the integral adjustable relief valve that returns liquid to the suction side of the pump if the discharge is blocked or over pressured.
Roper uses an inverted poppet design for this valve, deliberately built without the close fitting guides that can clog and hold a valve shut at the very moment it is needed. On the small 3600 frames the standard spring ranges are an A spring covering roughly 20 to 80 pounds per square inch and a B spring covering roughly 81 to 125, and a standard tempered steel spring is recommended up to about 350 degrees Fahrenheit with a stainless spring above that. One point is worth understanding before ordering: this style of valve protects in one direction of rotation only, though it can be repositioned to either side of the pump to suit the flow direction. Where protection is needed in both directions, the bi-directional valve style exists for that purpose.
Key Features
- Genuine Roper Pump Company relief valve faceplate assembly, part number N3-200
- Integral adjustable relief valve that returns liquid to the pump suction
- Inverted poppet design without close fitting guides that can clog
- Supplied complete with bronze bearings fitted and located
- Fits 3600 Series pumps across the 3611 through 4722 range
Applications
- 3600 Series heavy duty gear pumps in sizes 11, 17 and 22
- Transfer systems where a discharge valve can be closed against the pump
- Loading, unloading and mobile transfer packages
- Fuel oil, gasoline and solvent handling
- Adding integral overpressure protection during a pump rebuild
Specifications
- Brand: Roper Pump Company
- Part Number: N3-200
- Part Type: Faceplate assembly with relief valve
- Bearings: Bronze, supplied fitted
- Fits: 3600 Series 3611 through 4722
- Spring Ranges Offered: A spring approximately 20 to 80 pounds per square inch, B spring approximately 81 to 125
- Protection: Single direction of rotation, positionable to either side of the pump
- Condition: New
Frequently Asked Questions
Q: Does an integral relief valve replace a system relief valve?
It protects the pump itself, which is its purpose. Whether it is enough for the whole installation is a piping design question worth reviewing rather than assuming.
Q: How is the valve set?
With the adjusting screw, against a gauge, with the pump running and the discharge throttled in a controlled way. Setting it by counting turns is guesswork, since spring rate and installation both vary.
Q: Can the valve be used as a flow control?
No. Running continuously over the valve recirculates liquid inside the pump and heats it quickly, which damages the seal and the bearings. Control flow with speed or a bypass loop instead.
Q: What if my pump reverses direction in service?
Then single direction protection is not enough on its own. Roper offers a bi-directional valve style for reversing duty, available on the 11, 17, 22, 32, 43 and 48 sizes.
Not sure this is the right part? Send us a Picture of the pump plate on your pump and the CLR Marine team will confirm the correct relief valve faceplate assembly before you order.
CLRMarine
