advice on an old bristol pump

[gilly-06]

hi guys looking for some advice

bought this compressor last week its most likely 2x the age i am lol

but i got it for a mere £100 + fuel costs which i thought was a bargin

ive ran it and ive had it up to 150 psi and all works well

but decided to give the pump a thuro check as its proberly due one

the guy i got it off said it was too big for him for what he needed

heres some pics and ill let them do the talking

in all its glory (originally green by the looks of it )

now the bristol pump its self (ive had it partially stripped and put it back together to take pics )so some pipes are loose lol

top outlet to tank - bottom water cooling ??

2 air/oil pipes - water inlet ??

im guessing oil pump ??

now internal pictures

(oil pump area how i found it in a poor state )(8 new ball bearings needed)

crank and conrod both in good condition a little side-side movement but otherwise nice and smooth

head off and top of piston has an oily surface with crap on top
(a wipe with a cloth looked brand new again )

bore is nice and smooth

and finally the head its self
(note the little hole goes to one of the pipes i thought was an oil pipe )

so this is my new project

can anyone shed light on the pump and the area with the damaged internal parts


thanks and hope yous like the read

gilly

 

[normspanners]

looks like it should be water cooled ? the two male threaded connections one in the cyl head and the one in the bottom of the cyl will be the cooling connections but the 'pump' bit with the metal 'rocks' looks weird, how have they worn like that without distroying the retaining plate ?
The pipe that connects to the hole in the head with the cooling fins on it, where it connects to the 'pump' is there some form of jet or valve ? because you would loose all the compression through it because it returns to the top of the inlet reed .
I have had athought maybe its a freon compressor pump off a freezer unit and been converted to a compressor, I had one I converted, it worked for years with no problems at all and VERY quiet untill I needed more air capacity.

 

[normspanners]

Just had search and bristol make recipricating pumps for refrigeration air conditioning so the 'pump' is not needed I wouldn't have thought.
Mine had the inlet going into the sump above the oil and the inlet reed was in the piston crown if I remember correctly ( it was 35 yrs ago ) but did not 'produce' oil in the tank in any large quantity but it did 'use' a small amount of oil over 12 mths. so maybe this is a variation of the same 'theme' as your 'pump'.

 

[rtbcomp]

We had a water-cooled refrigeration pump at a mink farm I worked on. It ran a small freezer room and the warm water was fed round the drinking system to stop it freezing in winter.

 

[gilly-06]

thanks for the help guys the 'pump' bit where the rocks are when i removed the plate the rocks where sitting at the bottom and the rest fell out

the brass part with the hole in it has a hole in it with a ball bearing and a spring which either connects to the centre some how

on a search the set up looks similar to a bristol duplex pump

it didnt seem to leak any air threw it so im guessing the brass part was doing its job in a way
do yous think a car power steering pump would be ok to use as a water pump driven by the belt ??


thanks gilly

 

[rtbcomp]

A power steering pump should have the capacity, whether water will lubricated it satisfactorily is another matter.

The one we had convection fed into the header tank which fed the drinking water to the cages.

You could try a washing machine pump or a central heating pump?

 

[normspanners]

Personally I would just have a steel or copper container with a filler cap VENTED to atmosphere on top and have the container directly along side the compressor, it forming a columb of water from the bottom connector then 200mm ish higher than the cylinder head and let convection do the job, there are a lot of static engines cooled in this fashion and they BURN their fuel, as long as the container had a largish surface area equallish to the combined surface area of the fins of a 'normal' compressor, it would be perfect and probably work better than any normal air cooled compressor by keeping the air cooler because cool air is denser, (more dense?), than hot air.
Maybhehe it's me thats denser!!?

 

[normspanners]

ps I would block off the two pipe connectors at either end and throw the rocks etc away then that cannot cause any probs in the future.
I wonder if that was some kind of seperator to knock/centifuge/seperate the oil from the freon ?then the oil would return to the sump?

 

[eil]

The device with the bits of ball bearings on the end of the crank is probably a centrifugal unloader arrangement, weights spin out seals the port pressure builds up, pump stops weights move back in exhausts high side of pump at inlet valve, something like that anyways.

 

[rtbcomp]

Would they have an unloader on a closed-circuit refrigeration pump?

 

[gilly-06]

again thanks for the reply's everyone its much appreciated and yes it would seem it is unloader of some sort yeah ill have to block them off if they are no use and leave the parts that are of no use out but ill still keep the pipes all connected so to keep it looking origional


well ill empty the rest of the oil out it re seal it back up and put fresh oil in it is there any oil in perticular i should use


so basically a centrifugal unloader helps startup to minimise the load on start up ??


again thanks for all the help

gilly (kevin.)

 

[eil]

I'm not entirely convinced thats its a refrigeration compressor as I would expect to see a king valve or similar on/in the head, yes bigger refrigeration pumps might well have a means of unloading.
Its a fine looking unit though water cooled, you could do with that plenty of hot water for a bath after blasting your scooter with that Rog.

 

[eil]

again thanks for the reply's everyone its much appreciated and yes it would seem it is unloader of some sort yeah ill have to block them off if they are no use and leave the parts that are of no use out but ill still keep the pipes all connected so to keep it looking origional


well ill empty the rest of the oil out it re seal it back up and put fresh oil in it is there any oil in perticular i should use


again thanks for all the help

gilly (kevin.)

What kind of non return vale is on the receiver Kev, shame not to try and get it working as it should though.

 

[normspanners]

dont use detergent oil, use, sae 30 40 comp oil to save glazing bores etc

 

[rtbcomp]

............plenty of hot water for a bath after blasting your scooter with that Rog.

When I installed my hot water cylinder I added an extra heating coil with the idea of recovering heat from my fridge pump setup, but never got round to it.

 

[gilly-06]

yeah im not sure either if its a refrigeration unit although mabe used on a tractor or similar for hammer drills or similar

as the name plate on the side has

pneumatic
tools

bristol
england

the only one way valve i can see where the unloader is is the brass bit with the hole in it has a ball bearing & spring inside it aswell but i do think its well worn

yeah i would like to get it running the way its supposed to

ill need to get some ball bearings and study some diagrams of unloaders and get it working again

just means i can use it in the mean time while sourcing/making parts and not causing any damage to it that was my main worry

the air inlet where the other pipe joins to i can blow threw it or suck threw it

ill upload some more pictures of the inlet part (it just unscrews out )

thanks gilly . kev

 

[normspanners]

Ps I cant see it being an unloader because as the motor turns at a set speed, so the balls would spin out anyway ?

 

[eil]

Ps I cant see it being an unloader because as the motor turns at a set speed, so the balls would spin out anyway ?

Unloads at rest Norm.

 

[eil]

Similar to http://compressors.tpub.com/TM-5-4310-362-14/TM-5-4310-362-140030.htm

 

[gilly-06]

dont use detergent oil, use, sae 30 40 comp oil to save glazing bores etc

thanks norm i was going to use motor oil but again i would rather i used the correct oil to protect it

yes the unloader seems a handy addon to have