Roper Pump D11-257 Case Gasket for A Series 06 to 75
The Roper D11-257 is the case gasket fitted between the pump case and the adjoining plate on A Series gear pumps in the 06 through 75 displacement sizes, and on the 2919 figure. In an external gear pump this gasket does two jobs at once. It seals the pumped liquid inside the casing at the parting line, and its compressed thickness forms part of the end clearance between the gear faces and the plate they run against. Fit the wrong thickness and the pump either bleeds capacity back through an oversized clearance or drags and heats up through one that is too tight.
A case gasket is a single use item. Once it has been pulled down and has taken a set against the machined faces it will not seal dependably a second time, so a fresh one belongs in every teardown no matter how sound the old one looks coming off. Gaskets are also the first thing to suffer when a pump runs hotter than it was specified for or sees a fluid it was never rated for. The tell-tale signs are weeping at the parting line, a dried band of product around the joint, and case bolts that feel slack after a few hours of running. Scrape both faces clean and check them for nicks before the new gasket goes on, because no gasket can bridge a damaged sealing surface.
Key Features
- Genuine Roper Pump Company case gasket, part number D11-257
- Cut to the A Series case profile so bolt holes and port openings line up without trimming
- Sets part of the running end clearance between the gear faces and the adjoining plate
- Seals the parting line so pumped liquid stays inside the casing
- Single use design meant to be renewed at every teardown
Applications
- A Series gear pumps in the 06 through 75 displacement sizes
- Pressure lubrication and bearing oil supply systems
- Fuel supply, day tank and boiler feed service
- Tank battery recirculation and fuel additive dosing
- General clean liquid transfer on foot mounted or C-face pumps
Specifications
- Brand: Roper Pump Company
- Part Number: D11-257
- Part Type: Case gasket
- Fits: A Series gear pumps sizes 06 through 75, and figure 2919
- Function: Parting line seal and end clearance shim
- Pump Family: A Series helical gear pumps, cast iron housings with bronze journal bearings
- Condition: New
Frequently Asked Questions
Q: Does gasket thickness really matter if I cut my own from sheet stock?
It matters more than almost anything else in the rebuild. A hand cut gasket that is a few thousandths off moves the gears relative to the plate they run against, and the pump reports it as lost capacity or as a climb in power draw. The cut part removes the guesswork.
Q: What bolt pattern should I use when I pull the case back together?
Work in a criss cross pattern across two or three passes rather than taking one bolt down fully at a time. Even loading is what keeps a thin gasket from being crushed on one side and left proud on the other.
Q: Should I coat it with sealant before assembly?
Roper case gaskets are designed to seal dry. Sealant adds thickness you cannot measure and can be washed into the pumped stream, so leave it off unless the service instructions for your machine specifically call for it.
Q: How should spare gaskets be stored?
Flat, dry and out of direct sunlight. A gasket that has been rolled, creased or left on a hot shelf can take a permanent set and will not lie flat against the case when you finally need it.
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 case gasket before you order.
CLRMarine
