Hot gas pipe size reduction advice?

[monkey spanners]

Have a 7/8" hot gas pipe i wish to reduce to 3/4" before it goes up about 2.5m to the condenser.

A: I can either reduce it with a fitting and then a 3/4" elbow, which will leave a step in horizontal pipe before the reduction.

Or,

B: I can use a 7/8" elbow and then reduce it to 3/4" which to me looks a better option as there is no step for oil to pool behind.

C: I'm over thinking things again, makes no difference :D

Which is better A or B? or C the correct answer!

Its a 7.5hp Scroll on R404A around 20Kw duty i think!

Cheer Jon :)

[r.bartlett]

You're overthinking this.... However I use a 7/8 elbow then reduce to 3/4

(actually I'djust bloody crimp the pipe instead esp if it was being lagged!)

[install monkey]

refer to manufacturers installation instructions-cover yourself- and get cash upfront before u start- dont get sidetracked with cups of camomile and rosehip tea!

[Magoo]

Use a discharge check valve and keep it 7/8 "

[monkey spanners]

RB, thats the plan! think it looks nicest....

IM, no install manual as its a monkey made system from bits! Find out tomorrow if the condenser fits on the wall....

Magoo, its got a check valve in the 7/8" that compe off the compressor so that will stop any liquid getting back to the compressor on offcycle, got the pipes sized at 1 3/8" suction 5/8" liquid and 3/4" hot gas by the wholesalers tech dept and have the pipe etc on site so will likely stick with it unless its seriosly wrong!

Thanks for the replies :)

[Magoo]

Hi MS
all cool, just that I err on the side of caution with remote condensers, the vertical lift the check valve the elbows and the U bend into condenser all is pressure resistance with pull down loads etc.. The discharge on compressor can ramp quite high on restarts. Particually here with high ambients outside in summer.

[monkey spanners]

I got the condenser oversized to cope in the summer if they melt all the ice and warm the water up, so most of the time its way too big. There are noise issue on site so this suits as i have fan speed controllers on it too.
It should only run at night time on cheaper electric, but if the other system fails it will need to run 24hrs a day so is (hopefullly) designed to cope in all weathers!

Will take some pics if and when i get it finished!