Jump to content
  • 0

Pumping up the 'Actuator's?' on an Alvis Saladin, in Southampton area.


sallidan

Question

14 answers to this question

Recommended Posts

  • 0

I know they are supposed to be filled with inert gas or something but we have just had an bloody great screw type air compressor delivered at work that has and air drying plant on it. It produces "dry" air and is all computer controlled ect. Would it be ok to pump up an actuator using this....Oh hang just thought it only runs to 150psi so probably not...sorry just a thought...

Link to comment
Share on other sites

  • 0

Cheers for that, PM = Private Message, yes ?. I'll have crack it . Ta.

 

Hi, I would recommend you send a PM to Oily, as he owns a Saracen, and is located in the Southampton area. Though if you find that your accumulators are knackered, I am in the process of having seals made up for them.

 

Simon

Link to comment
Share on other sites

  • 0
No, it was argon. BTW, the bus garages in London, laterly used to charge the Routemaster accumalators with compressed air. It worked, but needed charging more often.

 

Simon,

 

Dry charged air is what was always used by the Army for Saracen, Saladin, and Leyland, we had small bottles for ease of use, which were charged by a special compressor with an air dryer. As far as I am aware, London Transport had always used air as well for Routemasters. Whilst working for the army, other equipment came in service, such as Scammell EKA, Terex loading shovles, etc, with nitrogen charged accumulators.

Link to comment
Share on other sites

  • 0

Hi, I thought a note on what can go wrong if compressed air was used that had traces of oil in it.

 

Many years ago 1983ish when I worked in the oil industry I was offshore Port Said, about halfway between Egypt and Cyprus. Part of the equipment on the oil rig is a mud pump, a very powerful machine that pumps drilling fluid (bentonite mud) so that it circulates through the drill string and then up the drilled hole cleaning out the drilled cuttings. This pump had the equivalent of accumulators such as will be seen on the Saracen, in the Saracen's case to have a reserve of pressure, in the mud pump to balance out the reciprocations of the piston.

 

The accumulator in this case was a huge steel ball shaped device with a bolted plate on top that was at least 1.5 inches thick. The mud engineer had topped up the pressure from cylinders marked nitrogen but in fact had been filled locally with air. When the pump started, the accumulator exploded, driving the top cap (having stripped 10 or so very large bolts) through a cable duct and on through the ri floor, another inch or so of steel.

 

I remember all this very vividly as just 2 hours before I was working directly above and in the path of the top cap.

 

Basically, compressed air with even the smallest amount of oil under high pressure is explosive.

 

The pictures show before and after, and the cap with a hand to show scale and some of the damage

 

 

image10.jpg

image14.jpg

image21.jpg

image6.jpg

Link to comment
Share on other sites

  • 0
few reasons why nitrogen is preferred , its inert, and molecules are comparably large so leak rate is slower

 

There are different grades of Nitrogen so it is best to ensure it is what is called "oxygen-free Nitrogen", as it is the oxygen and oil that do not mix.

 

Simon, it always made me wonder with Saracens, etc using accumulaters, as the pistons seals are archaic in design and after a period the compressed air passes into the hydraulic system, recharging being a regular operation when in service. The army spec was to use dry charged compressed air throughout their service life.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Answer this question...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...