Nipple Hex Connectors Am I Doing Something Not Quite Right?

[Pollys13]

I've been getting a few connectors for my air supply system.
I've ordered some hex nipple connectors I think they are called. One a NPT 1/2" male-BSP 3/8"
Male Cone Nipple Adapter Ebay item number 121255605176.
Thisis intended to connect my NPT 1/2" watertrap to female port on 3/8" BSP ball valve.
When I tighten these nipple connectors into the components I'm joining together, as I tighten up the nipple
It tightens up on one end but releases on the other end? I could rotate a component onto the nipple to fit it on tight.
Though then how do I insure the componets are all lying down flat on the mounting board, Am I doing something not quite here?

 

[rtbcomp]

It tightens up on one end but releases on the other end? That's because they're both right hand threads.

Rotating tightening up before mounting is OK - the unions shouldn't be tightened so far that they lock up. Some PTFE tape on the taper thread may help.

Can you introduce a compression or swivel cone fitting somewhere if you want to tighten it up after mounting them flat?

 

[Pollys13]

This is how far I've got,
Connecting the air line one end to quick release coupler on compressor, the other end of air line to 3/8" ball valve.
Other side of ball valve to NPT 1/2" female port.
So you can see how far I've got so far, compression fitting/s. I see there are several sizes available, where could
I fit to keep components flat on board? How do I connect up to what I already have, I think it might be what you call a reducing bush?
Cheers.
Peter.
3/4 turns ptfe tape round all threads
Air Supply Fittings Bought So Far 27th May.
Two of 1/2" x 1/4" bsp femail to femail union 281589689399 to connect Draper air hose which has a 1/2 " BSP male fitting on end
£1.89 inc delivery
To join Draper air line via a uni hi flow 1/4" BSP male adapter I have several of these already.
The other one fits on other end of draper air line and is connected into the F-F ball valve via
a Draper 25826 3/8" male to 1/4" bsp male taper reducing union 191428918897 buy now inc delivery £2.21
One of NPT adapter 121255605176 to connect 3/8" bsp ball valve to 1/2" NPT water trap
NPT Male-BSPP Male Cone Nipple Adapters For Air and Hydraulics,NPT Connector
1/2 NPT Male Nipple, 3/8 Bsp Male £3.19 buy now inc delivery

On photo how he has set his up, he has arranged to run two pots, I'm only using one.

 

[Rig Pig]

Build up the stack of components one at a time, spinning each one on holding the last componant fitted in a vice or workmate, use a spanner on the hex to stopit tuning. offer the stack up to the board or bench to check it's all parallel. I prefer Loctight thread sealant to tape.

 

[Pollys13]

Build up the stack of components one at a time, spinning each one on holding the last componant fitted in a vice or workmate, use a spanner on the hex to stopit tuning. offer the stack up to the board or bench to check it's all parallel. I prefer Loctight thread sealant to tape.

OK cheers.

 

[rtbcomp]

I use Loctite on parallel threads except where they go into aluminium components like regulators then I use tape. This reduces the chance of stripping the thread when dismantling.

I prefer tape on taper threads, it gives some scope for adjustment.

 

[Pollys13]

I use Loctite on parallel threads except where they go into aluminium components like regulators then I use tape. This reduces the chance of stripping the thread when dismantling.

I prefer tape on taper threads, it gives some scope for adjustment.

OK cheers.

 

[Pollys13]

Build up the stack of components one at a time, spinning each one on holding the last componant fitted in a vice or workmate, use a spanner on the hex to stopit tuning. offer the stack up to the board or bench to check it's all parallel. I prefer Loctight thread sealant to tape.

If I can't get them flat on the board using PTFE tape. Can I get them flat on the board even though thread joint might be a little loose so parts are flat on the board. Would the Loctight sealant seal up any loose threads and be strong enough to lock them together a bit like a glue would?

 

[Pollys13]

I use Loctite on parallel threads except where they go into aluminium components like regulators then I use tape. This reduces the chance of stripping the thread when dismantling.

I prefer tape on taper threads, it gives some scope for adjustment.

Could you give me your view on this too? " If I can't get them flat on the board using PTFE tape. Can I get them flat on the board even though thread joint might be a little loose so parts are flat on the board. Would the Loctight sealant seal up any loose threads and be strong enough to lock them together a bit like a glue would? " Cheers.

 

[rtbcomp]

That's the point of using a tapered male thread into a parallel female one using tape. There is sufficient give in the tape to give a good seal without overly tightening the fittings. Use 3 or 4 turns of tape.

Loctite pipe sealant will give a good seal on moderately tight joints, and allow them to be undone without too much trouble, although as I said I don't like using it on soft aluminium threads. Hand tighten the joint and then use a spanner for the final turn, stopping when everything is aligned properly.

Note that some joints seal on the mating surfaces and not the threads, don't use tape or loctite on these.

 

[Pollys13]

That's the point of using a tapered male thread into a parallel female one using tape. There is sufficient give in the tape to give a good seal without overly tightening the fittings. Use 3 or 4 turns of tape.

Loctite pipe sealant will give a good seal on moderately tight joints, and allow them to be undone without too much trouble, although as I said I don't like using it on soft aluminium threads. Hand tighten the joint and then use a spanner for the final turn, stopping when everything is aligned properly.

Note that some joints seal on the mating surfaces and not the threads, don't use tape or loctite on these.

Ah, right, I see I think So I should be looking at fittings with a bspt male thread going into a fitting with a female parallel bsp thread,which I understand by international convention female threads they have to be. if available not looked yet. This is going to scramble my brain
Cheers.

 

[AndyStobbs]

You're making a mountain from a mole hill here fella. Screw your bits up, one after the other and get them inline by eye. Place on board and screw down, sorry to be blunt but it isn't rocket science. Less questions more screwing and you'll find yourself wondering how it scrambled your brain in the first place.

 

[Rig Pig]

If in doubt brake out the big shifters!