Burks 9699 Viton O-Ring 3.984 in ID
The Burks 9699 is the genuine Burks Viton o-ring, 3.984 in inside diameter. It is a static seal: squeezed between two machined faces, it fills every small imperfection in them and blocks the path liquid would otherwise take out of the pump.
Nip, extrusion and set are what finish these rings. Over-tightening pinches the ring, high pressure can push part of it into the clearance gap, and long service at temperature leaves it permanently squashed. None of that is visible until the pump is apart, so the sensible rule is to replace the ring at every teardown rather than judge it by eye.
Material is the part of this number that matters most. Viton is what Burks fitted here, and swapping compounds changes what the pump can safely handle - temperature range, and which liquids will attack the seal. Burks lists the same physical size in several compounds for exactly that reason, so match the material as well as the dimension.
Key Features
- Genuine Burks replacement in Viton
- 3.984 in inside diameter
- Direct replacement for the original Burks seal
- Static seal designed to be renewed at every teardown
- Holds pressure without over-tightening the joint
- Inexpensive insurance against a leak after reassembly
Applications
- Burks pump service and overhaul
- Reassembling a pump after a seal or impeller change
- Curing a weep or drip from a casing joint
- Replacing a ring that has gone hard or taken a set
- Restocking a spares kit for planned maintenance
- Industrial, marine and dockside pump installations
Specifications
- Brand: Burks
- Manufacturer: Crane Pumps and Systems
- Manufacturer Part Number: 9699
- Part Type: O-Ring
- Material: Viton
- Size: 3.984 in inside diameter
- Condition: New
Frequently Asked Questions
Q: Should I lubricate the ring before fitting it?
A light smear of a grease compatible with the ring compound helps it seat and stops it rolling or pinching as the joint closes. Avoid petroleum grease on EPDM, and avoid anything that will contaminate the liquid you are pumping.
Q: The old ring looks fine. Can I reuse it?
It is not worth it. A ring that has been under compression has already taken some set, and the cost of a repeat teardown is far higher than the ring. Seals of this type are treated as single-use items across the industry.
Q: What tightening sequence should I use on the joint?
Draw the fasteners down evenly in a cross pattern in two or three passes rather than pulling one side home first. Uneven closing is what pinches a ring and leaves it nicked on one edge.
Q: Can I use a generic ring from a seal kit instead?
A generic ring in the same nominal size will often sit in the groove, but the compound, the shore hardness and the cross section tolerance are what Burks specified. Those details decide whether it seals for years or seeps in a month.
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 O-ring before you order.
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