Manhole Cover Care and Maintenance

Helpful advice to keep your manhole covers in tip top condition for years to come

Thrubeam covers and frames can only perform to the highest standards if they are routinely checked and maintained in accordance with our guidelines outlined in our brochures, available for download below. Cleaning of seals, frame seating faces and cover edges at each lift is essential.

Correct seal installation

The following is a guide on how to install a new D400/C250 manhole cover seal correctly.

An outline for replacing seals can be found in the D400 Installation / C250 installation guides section of this site, however we will explain the process in more detail here.

The first step is to remove the damaged seal. This can be done by using pliers or similar tool in order to remove a section of the seal out of the cover.

Once a section has been released from the groove of the cover then the rest can be pulled out by hand. When inserting the new seal ensure that the orientation is correct.

Seal Replacement - Care & Maintenance - ThruBeam

Excess seal issues

An issue that can occur when installing a new seal is the appearance of excess seal as shown in the image above.

This is not due to the seal being too large but is instead due to the seal being pulled too tightly as it was being fitted.

By removing a portion of the seal from the grove on either side of this will slacken the seal. Then it can be refitted into the grove correctly.

The following image and video demonstrates how to solve this issue.

Excess Seal Issues - ThruBeam

We hope this provides useful information on seal installation and replacement. However for further help and advice, please do not hesitate to contact us.

ThruBeam's Care & Maintenance Brochures

download C250 Care and Maintenance Brochure (PDF)

C250 Care and Maintenance Brochure (PDF)

download D400 Care and Maintenance Brochure (PDF)

D400 Care and Maintenance Brochure (PDF)