Lockerwahsers? Fasteners for Sealing Joints 1

[CTWELSH82]

Transmission Substation Electrician. Lately we've had a lot of discussions on fasteners on Oil filled and gas filled electrical equipment. It seems in most cases no springwasher or Bellville is used to join surfaces that are sealed with an o-ring or groove gasket seal. We use Bellvilles for electric connection and springwashers or pal nuts on structures. What is the reasoning for not using a some sort of positive locking fastener for sealing joints?

 

[TugboatEng]

Every type of lock washers with the exception of the Belleville spring type creates a flow path for water or corrosive materials to get to the threads of the bolt. Lock washers should be avoided whenever possible.

 

[hydtools]

Use sealing washers. Properly torqued fasteners should not need locking devices, unless vibration conditions require some sort of fastener lock. Consider thread locking sealants.

Ted

 

[dik]

I spec Loctite 263('Red') nearly always, for anything that can loosen, or for sliding connections that I don't want the nut to 'fall off'.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[LittleInch]

Sealing joints normally need quite a lot of bolt force. This stops the nut coming off.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[dik]

Belt and suspenders, I guess... when I have heavy vibrating mechanical equipment overhead, where the fasteners are loaded in tension, I rest a little easier knowing that they will stay put... Loctite Red is better than glue... For sliding connections, you don't have the luxury of 'snug tight'.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[CTWELSH82]

Thanks for the responses, but ultimately my question is "Why not". Why would the MFG not use positive locking methods in this connection. I even read in a MFG manual "All frame connections, utilize split washer. DO NOT use split washers for any gasketed cover or pipe connection, refer to Torque table" . These aren't sliding connections, They are one side flat to one side with O-Ring or gasket groove.

 

[dik]

Split washers don't work very well; they are unreliable.

https://www.boltscience.com/pages/helicalspringwashers.htm

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[LittleInch]

Why not?

Because they take extra effort and cost and you don't need them.

Could do with a drawing or a sketch here.

Joints tend to have a decent amount of bolt length between bolts. Electrical connections much less so there is so much less bloat length to get some stretch.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[CTWELSH82]

Thanks again. Just thought there might be a possible negative impact, as the MFG expressly said Do Not for some and DO for others.

 

[TugboatEng]

Perhaps we need to reverse the perspective. You tell us why you think you need lock washers.