FLAT GASKET INSTALLATION TIPS

By flat seals we mean both traditional seals cut from gasket sheets, as well as SWG spiral seals, kammprofile, corrugated, envelope, as well as static seals made of sealing tape. The seal is the critical and most frequently serviced component of devices, so care in this area can bring great benefits to the user. To ensure long and effective seal operation, you must use basic and necessary knowledge in the selection of material and follow several basic assembly rules. 

1. Material selection

The proper selection of sealing material involves the analysis of several factors, such as: type of medium, chemical resistance, operating temperature range and permissible working pressure. Some of these factors can have a destructive effect on the components of the sealing material and lead to damage very quickly. 

 

2. Gasket thickness

The gasket should have the thickness specified in the documentation. Alternatively, you can consider the thickness of the removable seal, but you should take into account the degree of its settlement, usually from 30 to 60% of the thickness depending on the type of material. A gasket that is too thin may not guarantee sufficient tightness, and a gasket that is too thick may wear out quickly. 

 

3. Condition of collars

Before installing a new gasket, the rebates should be cleaned, any residues removed and ensured that they are smooth and parallel. 

 

4. Supporting materials

It is not recommended to use auxiliary agents or any lubricants, their presence may negatively affect the ability of the gasket material to transfer stress. On the contrary, the surfaces must be cleaned and dried before installing the seal. 

 

5. Seal dimensions

Make sure that the dimensions of the gasket are consistent with the documentation. The seal should not penetrate the duct and should be placed centrally. The minimum effective width of the seal should be at least five times its thickness. 

 

6. Preparation of bolts

If necessary, clean any debris from the threads of the bolts and nuts. You should also make sure that the nuts move freely. It is recommended to lubricate bolts and nuts with grease, which leads to a reduced difference in bolt tensions and a more even distribution of stresses on the gasket. 

 

7. Bolt tension

The applied bolt tension should ensure the appropriate "operating point" of the seal. Too high a tension causes faster degradation of the sealing material, and too low a risk of joint leakage. The documentation should be followed or the tensions should be determined based on appropriate calculation factors. 

 

8. Installing the seal

The process of tightening the bolts should take place in several stages. First tighten the bolts by hand. Then tighten the bolts using the following steps: 50%, 80% and 100% of the required tension. These activities should be performed while maintaining an alternating sequence of tightening the bolts using a torque wrench. 

 

9. Tightening the bolts

Following the above recommendations should eliminate the need to tighten the bolts later. However, if it proves necessary, this operation can only be carried out after the installation has been turned off and cooled down. 

 

10. Use of recycled gasket

The gasket material has limited elastic recovery and degrades after each operating cycle. Each time the connector is disassembled, the seals should be replaced with new ones, both for safety and economic reasons. The costs of dismantling the joint and the risk of leakage are many times higher than the costs of a new gasket.