pipe fittings confusion

[NBTC]

Hello all
I am after some advice on brass steam pipe fittings, I have spent the day trying to figure out what I need to make up some new pipes. I am new to pipe making so have managed to completely confuse myself so here goes. The pipes I need to make are as follows:-
1/4inch x 40tpi fitting to 3/8inch 32tpi preferably 5/32 pipe ( water tank feed to hand pump )
1/4inch x 40tpi fitting to 5/16inch 40tpi 5/32 pipe ( boiler to engine inlet )

TPI figures above I am not totally sure about so will purchase both 32 and 40 union nuts

I have looked at reducing unions but these seem to be for standard sizes so wondered if it's common practice for odd sizes to use large ferrules and bulk silver solder onto the pipe to ? Can you get ferrules for say 3/8 inch Union nut that fit 5/32 pipe I can't fing anything so far on the Internet.

Any advice help appreciated as I don't have a lot of hair to pull out.

 

[Jasonb]

3/8 x 32 is a big thread for 5/32" pipe, probably have to make your own custon ferrule/nipple that is sized externally for the 3/8" nut/male spigot and internally to be a nice fit on the 5/32" pipe don't use solder to bulk it out a sit won't. If you can't make the nipple then a turned parallel sleeve can be put into a larger nipple probably 1/4" OD and the 5/32" pipe into that.

 

[NBTC]

Thanks Jasonb unfortunately I don't have any machining capabilities at present so trying to see what I get off the shelf maybe a reducer on reducer or even a silicone pipe on the water tank 3/8 side to pump as that's the low pressure side but I prefer brass piping so will see what I can cobble together.