Cap for gas line needed

[Bruce King]

Thanks guys!
I just realized the fitting I bought was in the wrong bag which added to my confusion.

[Michael J Evans]

Bruce,
Is this a fitting for flexible tubing or rigid pipe you need?

The convoluted flexible tubing known as CSST has its own special sized variation of a flare fitting similar to SAE 45* flare, but different. If you have the convoluted tubing you will need to go to a fireplace /gas shop to get that fitting.

If this is rigid pipe then it is NPT thread ( national pipe thread). Measure the inside & outside diameter of the male threads. Pipe is supposed to be called out by it's inside diameter so if it's . 75" inside it's supposed to be 3/4" pipe. But due to different schedules that isn't always the case. If your pipe measures 5/8 on the outside of the male, I believe it would actually be 3/8" pipe (nominally sized).

[Stan Coryell]

Bruce,
Is this a fitting for flexible tubing or rigid pipe you need?

The convoluted flexible tubing known as CSST has its own special sized variation of a flare fitting similar to SAE 45* flare, but different. If you have the convoluted tubing you will need to go to a fireplace /gas shop to get that fitting.

If this is rigid pipe then it is NPT thread ( national pipe thread). Measure the inside & outside diameter of the male threads. Pipe is supposed to be called out by it's inside diameter so if it's . 75" inside it's supposed to be 3/4" pipe. But due to different schedules that isn't always the case. If your pipe measures 5/8 on the outside of the male, I believe it would actually be 3/8" pipe (nominally sized).

That isn't a CSST fitting. It's a flare adapter. Probably for a flex hose, like to hook up a stove.

IPS, regular threaded pipe, is not measured by ID or OD. It is called out as a nominal size. 3/4 = 1.05 OD, 2 = 2.375, 4= 4.5, 14 = 14
ID depends on schedule or wall thickness. Standard pipe is Schedule 40.

Copper pipe measures nominal plus 1/8". 1/2= 5/8, 2= 2 1/8

Tubing is measured OD. 1/4 = 1/4

[Michael J Evans]

That isn't a CSST fitting. It's a flare adapter. Probably for a flex hose, like to hook up a stove.

IPS, regular threaded pipe, is not measured by ID or OD. It is called out as a nominal size. 3/4 = 1.05 OD, 2 = 2.375, 4= 4.5, 14 = 14
ID depends on schedule or wall thickness. Standard pipe is Schedule 40.

Copper pipe measures nominal plus 1/8". 1/2= 5/8, 2= 2 1/8

Tubing is measured OD. 1/4 = 1/4

Stan,
Attached is a picture of some 3/4" pipe, from a old 3/4" pipe clamp in my shop... It measures 3/4"... You are correct in that pipe is nominally sized (see my original post). Pipe was originally designed based off its internal flow dimensions, but like all things has evolved over time. pipe 2.jpg

In regards to the fitting,
Your fitting appears to be made of steel. typically SAE FLARE (45 degrees) are made of brass and JIC Fittings (37 degrees) are made of steel. You typically see SAE 45 used in Gas,HVAC, automotive applications and JIC used in higher pressure hydraulic applications, but working in the fitting business I've seen both used in low pressure applications.
If your flare fitting is truly 5/8" or -10 size, then a SAE 45 flare cap or a JIC 37 Flare cap will both work for your application. In all sizes but -6 (3/8) & -12 (3/4) are interchangeable. The females & caps are generally all now cut with dual seats (37/45).
So you either need
-10 (5/8) SAE FLARE CAP, like item# N5-10
-10 (5/8) JIC CAP, item# 0304-C-10

[Michael J Evans]

Oh and with flare fittings you do not need pipe sealant or tape. Just hand tight & a 1/4 turn of the wrench.

[Bruce King]

I found one at a different store, 3/8 flare cap. Thanks for all the information!

[Stan Coryell]

[QUOTE=Michael J Evans;3085089]Stan,
Attached is a picture of some 3/4" pipe, from a old 3/4" pipe clamp in my shop... It measures 3/4"... You are correct in that pipe is nominally sized (see my original post). Pipe was originally designed based off its internal flow dimensions, but like all things has evolved over time. pipe 2.jpg

I disagree.
NPS pipe isn't measured by the ID. The ID charges with wall thickness.
The ID of 3/4 sch 40 pipe is .824"
At 14" the nominal diameter is the same as the OD.

That steel flare fitting in the picture looks like the fittings that come with the flexible gas line for hooking up an appliance, like a gas stove. I don't believe they can be bought separately. I wouldn't use it as an actual flare to pipe adapter in a pressure application.

[lowell holmes]

Take it to Lowes or Home Depot. Either store can help you.