Identifying and Measuring Manway Gaskets

Manway gaskets are the unsung heroes of brewery tanks, designed to ensure proper sealing and sanitary standards. Selecting the right gasket size and type is crucial. Read on for helpful steps to identify, measure, and size manway gaskets.

Manway Gasket Type

First, determine whether the gasket is round, oval, square, or rectangular. Also, look at the old gasket and groove to determine the shape and profile. These initial identifications help in selecting the right measurement method and ensure compatibility with the manway design.

Always refer to the tank manufacturer’s specifications if available to ensure compatibility in terms of size, material, temperature and pressure.

Popular manufacturers of manways include Premier Stainless Products, PBST Zhongde, Allied Beverage Tanks (ABT), Paul Mueller Company, Glacier Tanks, Rubber Fab, DCI, Inc., Cherry Burrell, CMT, Blackstone, and more.

BreweryGaskets.com carries replacement manway gaskets for these and other manufacturers' tank manways. Order online today with fast, free shipping.

Manway Gasket Materials

Select a gasket material that can withstand the specific conditions of the tank. Common materials shown below. Learn more in our resource section about brewery gasket materials.

• EPDM: Offers excellent resistance to heat, weather, and some chemicals.
• Silicone: Known for its high-temperature resistance and flexibility.
• Viton: Provides superior chemical resistance, making it suitable for harsh environments.
• Buna: Excellent resistance to oils, fuels, and petroleum-based products.

Measuring Manway Gaskets

For most round and oval manway door gaskets, we typically recommended finding the circumference and the cross section to match up the correct size. Thickness, Groove Width, Flange Width, Outer Diameter, Inner Circumference, Bolt Hole information are other references that may help in some applications.

Circumference: Outer circumference is a key dimension. You can obtain this by measuring around your door where the gasket fits inside or around the outside of your old gasket. It helps to use a flexible measuring tape, such as a tailor’s tape, for measuring the circumference as it can easily wrap around the gasket. If a flexible measuring tape is not available, you can use string. Wrap a piece of string around the outer edge, mark the overlap point, then measure the string length with a tape measure. This length is the circumference.

Cross Section: The other key dimension needed is the cross-section, typically of the long leg. You can get this dimension by measuring your old gasket or the distance of overlap from the door to the side of the tank. The cross-section is typically the sealing surface of the gasket—the rubber between the door and the tank or the door and the flange. Cross-section, or flange width, can sometimes also be measured as the distance between the inside edge (or inside diameter) and outside edge (or outside diameter) divided by two.

Pro Tip: Use the Circumference and Cross Section to look up and order manway gaskets at BreweryGaskets.com.

Outer Diameter: As an alternative or to help find circumference, you can use the outside diameter dimension. Use a measuring tape to measure across the gasket from outside edge to outside edge to get the outer diameter of the manway gasket or door.

Formula to Convert Outside Diameter to Circumference (if needed):
Circumference = π × Outside Diameter
Example for 20" OD Gasket:
Circumference = 3.1415 × 20 ≈ 62.83 inches

Thickness: For some gasket identification, it helps to also measure the thickness of the gasket. Use a ruler or better yet a caliper to ensure accuracy.

Bolt Holes: If the gasket has bolt holes, measure the diameter of the bolt holes, measure the distance between the centers of two opposite bolt holes (bolt circle diameter), and count the total number of bolt holes. Make a detailed note of all measurements.

For some oval gaskets or less common rectangular or square gaskets, when the circumference does not apply, measure and record the outside diameter of the length, outside diameter of the width, and flange width. For help on this and specialty sizing, consult the manufacturer or contact brewerygaskets.com for assistance.

Manway door gaskets come in a variety of sizes and styles, with different flange, lip, and groove profiles. Choosing the right gasket is key to preventing leaks and ensuring smooth brewing operations. Avoid downtime and keep delivering those delicious brews—visit BreweryGaskets.com for all your gasket and fitting needs.

Cheers to perfect brewing!

Read more in our published article about the role of manway tank gaskets in various steps of the brewing process.