The Importance of Torque

Torque is crucial when closing a manlid on a tank container or road tanker, and here’s why it matters 

1. Ensures a Proper Seal 

Applying the correct torque helps compress the manlid gasket evenly, forming a reliable seal between the manlid and the tank. If the torque is too low, you risk leaks; too high, and you might crush or damage the gasket 

2. Prevents Deformation or Damage 

Over-torquing can warp the manlid or damage the flange surface, especially if it’s made of softer materials. This can cause long-term sealing issues and increase maintenance costs. 

3. Safety Compliance 

Manlids are often used on tanks that hold hazardous or pressurised materials. Using the correct torque ensures the tank complies with safety regulations (e.g., ADR, IMDG, RID) and reduces the risk of accidents due to pressure release or chemical spills. 

4. Extends Life 

Consistent and correct torque application reduces wear on bolts, nuts, and the sealing surface. It avoids unnecessary stress on the assembly and keeps parts functioning properly over time. 

5. Uniform Pressure Distribution 

Even torque on all bolts ensures uniform pressure distribution around the lid. Uneven torque can lead to leak paths or cause the manlid to seat improperly. 

The Pelican Recommendation

As for a standard, we recommend a maximum torque value of 80Nm (60 lb-ft). Lower torque values can also be applicable, depending on the type of seal. Higher torque value is not advised as the seal might break, tear or start leaking. 

This recommended torque value applies to 4, 6 & 8 point manlid assemblies for cleaning hatches. 

For example: a Pelican Teftek® seal has a maximum torque value advise of 80Nm (60 lb.ft). This torque value is also applicable for standard PTFE braided manlid seals. 

The recommended torque range is printed on Pelican Teftek® seals to make installation easier.