Oswald Supply sells boiler manhole cover plates, rings, gaskets and hardware for ALL makes and models.  - Oswald Supply

For the past 90 years, Oswald Supply has been a leader in the industry, distributing manhole cover plates nationwide. Our manhole cover plates are made of pressed steel SA516-70. Low pressure and high pressure applications. 

Frequently Asked Questions

Q: I need a replacement manhole plate, but I may not have all of the information necessary. 

A: Not a problem. We have been selling replacement manhole plates since 1923. Our knowledgeable sales staff and trouble-shooting experts have the experience required to find you the right part. You can call us at 718-620-1400.

Q: What information do I need to know to narrow my search for the correct

Manhole Cover Plate Replacement?

A: The following information is always helpful when searching for the correct plate.


– Width and length (inside dimensions)


– Manhole Covers Elliptical

Boiler’s Working Pressure

– Low Pressure or High Pressure

Q: What are the standard Manhole Cover sizes?

A: 11 x 15, 12 x 16 and 14 x 18 manhole cover sizes are standard for the industry today. All elliptical shaped and flat. All of these sizes can be purchased directly from Oswald Supply. 

Q: I do not know the size of the Manhole Plate. How should I measure it?

A: It is best to measure the hole in the boilers shell, the one you are trying to seal with the handhole plate. Another more accurate way is to take the Inside Dimensions (I.D.) of the handhole plate itself. From shoulder to shoulder or hump to hump. Using a caliper is always helpful.

Q: Should I measure the Inside Dimensions of the gasket?

A: It is important to measure the Manhole Plate itself and NOT the gasket. The gasket could be warped and stretched out, or it could have been the wrong gasket in the first place.

Q: Why should I measure the Inside Dimensions of the Handhole Plate?

A: The width of the flange going around the handhole plate (“gasket seat”, or where the gasket sits) may vary plate to plate, more commonly seen on Cast Iron Handhole Plates due to old patterns. That’s why it is best to take the Inside Dimensions.

Q: What Shape is my handhole plate?

A: Manhole cover plates are typically Elliptical.

Q: What is the difference between Elliptical and Obround shaped Handhole Plates?

A: Elliptical (or Oval) plates look more like an egg. Obround (or Oblong) looks more like a race track; with parallel or straight sides.

Q: Are Manhole covers ever curved to the match the boilers shell?

A: Manhole covers are almost never curved to match the inside of the boilers shell. A ring is welded to the boiler shell, allowing a retrofit type design. Most rings come ¾” thick x 3, 4, or 5” deep. Ring diagrams can be found on the Oswald supply website. 

Q: Do I need a high pressure or low pressure manhole cover?

A: Oswald Supply manhole covers come in 300 pounds, 600 pounds, and 1000 pounds working pressure. All plates are made from SA516-70. 


Deja un comentario

Todos los comentarios son moderados antes de ser publicados