Help with yet another flow profiling modification

Need help with equipment usage or want to share your latest discovery?
User avatar
shawndo

Postby shawndo » Aug 01, 2016, 8:02 pm

I have a leak and am looking for guidance by someone who knows what they are doing!

Bottom line is that I finished my assembly but at the first pressure test, the initial 3/8 BSP connection from the water pump leaked. From what I've read, BSP connections are not supposed to use sealant, but I'm wondering if I need some kind of gasket or should I just put some sealant on anyway. Recommendations are helpful. I have emails out to the swaglok vendor and some other folks also.

(PS The ball valve is temporary until I get a solenoid valve and some 'lectricity learnin' done.)

Here is the bad actor:

Image

Some other photos of the assembly:
Image
Image
Darmok and Jalad at Tanagra

gor

Postby gor » Aug 01, 2016, 8:16 pm

That's a reducing nipple attached onto a one-way valve, so yes you do need to use sealant or Teflon tape to make a leakproof seal.

When you have a cone end (such as on the braided stainless hoses) then you don't need to use sealant or tape because the bsp threads take care of pressing the cone end against the fitting. It this case you get a seal from the metal 'ends' pressing against each other.

Bsp threads on their own, are not capable of making a seal and they need help by either using gaskets, Teflon tape or sealant.

User avatar
Peppersass

Postby Peppersass » Aug 02, 2016, 3:48 am

gor wrote:Bsp threads on their own, are not capable of making a seal and they need help by either using gaskets, Teflon tape or sealant.

Some of them seal with a copper crush washer. True of several fittings on the GS/3.

User avatar
Peppersass

Postby Peppersass » Aug 02, 2016, 3:53 am

Very cool mod. Did you make the tubes and fittings or did someone do that for you?

GlennV

Postby GlennV » Aug 02, 2016, 5:40 am

There are two types of BSP fittings. Parallel thread, which seal at the ends, and tapered, which seal on the threads. I don't know if this is what you have here, but a tapered male thread will seal on a parallel female thead if you use PTFE tape - as long as the thread doesn't bottom out. The other way round never works.

Rubbish picture (and it all needs some tidying up) but here is my version of the same mod (most of the fittings are 1/8 BSP - a mixture of parallel and tapered).
Image

User avatar
shawndo

Postby shawndo » Aug 02, 2016, 6:53 am

GlennV wrote:There are two types of BSP fittings. Parallel thread, which seal at the ends, and tapered, which seal on the threads.

The BSP connections are all parallel, so I do need to figure out how to seal them at the ends. It doesn't sound like any of the options are all that expensive. I'll try a little bit of everything.

Peppersass wrote:Very cool mod. Did you make the tubes and fittings or did someone do that for you?

All me with a sharpie, hanger, cutter, deburrer, and tube bender. Learning as I go. The copper is just soft enough that I can fine tune with elbow grease!
The minor goal was to line up the handle of the needle valve with the hole in the top panel that goes to the cooling tray, so I can adjust it by just pulling off the grate.

Image
Image
Darmok and Jalad at Tanagra

User avatar
erics

Postby erics » Aug 02, 2016, 1:28 pm

The first pic in your post looks to be a LM checkvalve (P/N A.2.011) screwed into the pump's 3/8" BSPP female discharge and sealed with a copper washer. On the other end of the checkvalve, it has 1/4" male BSPP threading which screws into the brass Swagelok fitting.

If the Swagelok fitting has BSPP female threads, about three wraps of teflon tape should effect a seal. A more proper way to do it would be to use a food grade thread sealer (Loctite or Loxeal or an equivalent) or a teflon crush washer. The teflon crush washer would be preferred but it needs to be thick enough to allow the male/female threading to create the crush.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at erols dot com

User avatar
shawndo

Postby shawndo » Aug 02, 2016, 2:02 pm

erics wrote: The teflon crush washer would be preferred but it needs to be thick enough to allow the male/female threading to create the crush.

Thanks!
I think teflon is the way to go. This is still early stages and I suspect i'll be taking it in/out a couple times before I'm done with it. I'll probably need a bag of washers.
Darmok and Jalad at Tanagra

User avatar
erics

Postby erics » Aug 02, 2016, 6:55 pm

Swagelok has the teflon gasket you need - P/N T-4-RJ-2 for "regular" or T-4-RJ-2-T for "thick". I would go for the "thick".
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at erols dot com

User avatar
shawndo

Postby shawndo » Aug 04, 2016, 8:20 pm

I got some teflon and copper washers. the thick teflon is a back-ordered from another warehouse, so I'll probably get some of those next week.

But fortunately not necessary, the copper crush washers did the trick! These go on the back of the male side as opposed to the teflon ones that go in the back of the female side. The dome in the back of the female bspp fitting was pretty large, do i'm not sure if the teflon gasket is reaching all the way back.

Now I just gotta learn about solenoid valves and this'll be a done.
Darmok and Jalad at Tanagra