Compressor testing

[iain/hsm]

Originally Posted by ppfsi

Wher do you get the drager tubes from and I assume you have to have the pump with it. Have searched the Drager site but cannot for love of puppies find the tubes on there Si

Just a note of caution before you buy these tubes, not on the web site due to specific factors to be considered. Each tube requires a fixed mass of gas (sample) in order to effect a chemical reation. The mass of gas is normally achieved by a combination of a measured flow rate and time. Some tubes will give a false reading if too much gas is supplied or for too long and each tube has its own specific sample rate and flow.

For our diving compressors or air compressor storage banks we normally supply a kit of four tubes. Carbon Dioxide, C02, Carbon Monoxide CO, Water vapour and Oil vapour. using the flow metered method, not hand pump.
Each tube cost is apx £5.87 and has a shelf life of two years. So £23.50 for one single test kit every three or six months, depending on compressor type, using the disposable tubes. Alternative is each tube supplied in a pack of 10 but the 40 tubes will set you back £183.00 and do 10 tests, over shelf life.

When using the simple flow meter and stop watch method.
1. C02 is reactant with a sample flow 0.2 l/min for 5 minutes or a 1litre sample size when using the 100-3000 ppm tube range

2. CO is the same sample flow and time when using the 2-300 ppm tube (however be aware some dive shops have been using the CO in Hydrogen tube by mistake)

3. Water vapour is more complicated as the new HSE guidelines require the maximum water content of air measured at the compressor system outlet to be less than 25Mg/m2
This requires a 2 l/min flow for 25 minutes. Or a 50 litre by volume FAC sample size.

4. Oil is the hardest of the lot to achieve a correct sample due to the variance in types of oils used in compressors. You will first have to find the compressor oil you are using before you can give a flow rate and time.

The method for sampling is using a small pressure reducing regulator (like a 1st stage ) with a small 0-5 l/min flow meter. These can be hired for about £24.00 per week.
A stop watch to measure time per sample and a report pad to self certify the air purity. In addition a small SOP standard operating procedure should be signed off before self certification. The reason I havn't given the part numbers is that within each gas there is a number of different tubes, you must first decide your test method, or test machine type before specific part numbers can be offered. Iain Middlebrook

[Phil Laughton]

Originally Posted by ppfsi

Wher do you get the drager tubes from and I assume you have to have the pump with it. Have searched the Drager site but cannot for love of puppies find the tubes on there

Si

Draeger tube are best obtained direct from Draeger Safety UK Ltd, and they will accept CC payment. You will need the Draeger book of detector tubes and equipment to identify which tube you require, and a price list. The phone number for Draeger UK is: 01670 352891 and ask for tube sales.
Because of the changes to the air purity standard (now BS EN 12021) oil and water vapours are difficult to sample, water vapour now 25mg/ cubic meter in depressurized air and oil vapour reduced to .5mg/ cubic meter, the Accuro hand pump isn't adequate. As Ian has said oil vapour sampleing requires a 50lt sample and a run time of 25min. The old Draeger Aerotest kit would cope but isn't made any more, and this is the reason I changed to a system that uses Kitagawa tubes, a pressure reducer and a flow meter. Both Kitagawa and Draeger tubes are only supplied in packs of ten and have a shelf life of only two to three years.
PM me and I can supply details of the equipment I now use.
Phil

[ppfsi]

Thanks for all the info you have provided me. As my company doesn't use that many cylinders of air a year I have decided to have my local dive shop refil them for me. Works out cheaper as it looks like the HSE were after official accredited testing of the air anyway.
Simon

[rnc]

I got mine from Bauer Kompressoren UK Ltd, St Helens (formerly SAS) telephone 01942724248. Expensive at £315 for 10 of each oil, CO,CO2 and H20 inc vat & p&p. And you still need the regulator/attachements!

[Phil Laughton]

Originally Posted by rnc

I got mine from Bauer Kompressoren UK Ltd, St Helens (formerly SAS) telephone 01942724248. Expensive at £315 for 10 of each oil, CO,CO2 and H20 inc vat & p&p. And you still need the regulator/attachements!

You Were Robbed!!
A set of tubes, for four tests, direct from Dreager UK would have set you back no more that £190 inc VAT. Carriage is included in the price of the tubes.
Tubes for use with the Simultan would cost just a little more than other short term tubes.
Dreager UK can be found on 01670 352891 ( Blyth, Northumberland)
Better luck next time.

Phil