Tapered & parallel

[mymini86]

Hi,all.

I found these on the air line coupler & adaptor. What is the theory behind it? Is it just for ease of fitting?

If the parallel work, why use tapered + PTFE?

Thanks in advance

 

[rtbcomp]

From what I can make out tapered are used to make a good seal whereas parallel are used for applications such as compression and cone seated joints, ie the thread itself isn't part of the seal.

 

[..DAZ..]

don't know of any theory behind it but from experience tapered threads give a much more secure joint and you don't have to use so much ptfe tape. you can also sometimes get away wothout using tape on tapered threads if you run out halfway through a job although not really recomemnded
daz

 

[piman]

Hello MM,

primarily tapered BSP is for pipe work and the like. Parallel only works with seals so a flat face is needed. I would imagine that the production of taper threads is more costly and also, depending on the fitting, getting the correct orientation is more difficult, e.g. elbows that line up to something.

Alec

 

[mymini86]

Thanks guys. Learn something new everyday.

 

[rtbcomp]

......, depending on the fitting, getting the correct orientation is more difficult, e.g. elbows that line up to something.

Alec

Acouple of layers of PTFE tape can help here.