Monthly Archives: May 2013

Compressed Air Supply Questions and Answers

Compressed Air Supply Questions and Answers

Before buying a compressor you need to know.

What pressure is required?
How much air will you need to use?  How many LPM or CFM.
Does the air need to be clean?
Does the air need to be dry?
Does the compressor need to be silent?  i.e. below 65 db.

Selecting a suitable air compressor.

Small Oil lubricated compressors are usually quieter but as they wear they can throw oil into the supply line which may or may not be an issue as some workshop machines or tools require lubrication in any case.

If clean air is the most important criteria, then an oil free compressor is what you require and addittional filters can be added to whichever specification you require.  If dry air is also important to prevent bacteria growth, then the oil free compressor will need to be fitted with a dryer.  Oil free compressors are also quiet when supplied in a dedicated soundproof cabinet.

Compressed air supply considerations

An air supply of up to 80 psi (5.5 Bar) is the pressure that you will find most small compressor units will supply but some provide less.  In house air (i.e. air supplied to a clean-room or workshop from a large central compressor) will likely be reduced by “pressure drop” due to an extended distance to the outlet or, by other users closer to the compressor.  Because of these issues, a small, dedicated compressor is sometimes the best way to keep the pressure and flow constant.

It is most important to know how much air i.e. how many LPM (litres per minute) or CFM (cubic feet per minute) the machine you are using requires, as well as the required pressure in PSI (pounds per square inch) or (BAR).

How the compressed air is generated

The amount of air supplied is determined by the volume which the pump unit can generate depending on its size or the speed it operates.  Overuse or leaking air will deplete the amount stored in the compressor’s tank and cause the pump to run, sometimes continuously.  Most compressors are designed to run 50% of the time and others are 100% rated, however, in a warm atmosphere, any compressor can overheat and in such circumstances it will fail.

At LPL we prefer that our customers ask our opinion to ensure they buy the correct compressor.

Ken Marshall
Director of Engineering
Laboratory Precision Ltd. ©


Which Vial Crimper Do I Need?

A question we hear many times a day but  the answer is not necessarily a simple one.  We will usually answer this with some questions about your assembly.

What type of cap are you using?

There are many types and sizes of crimp on caps available and it would be easy to assume that one size fits all or, near enough is good enough. This, however, is not the case.  Pharmaceutical sizes are generally termed as 11mm, 13mm, 20mm, 28mm and 32mm with some variations in between.  Some caps are of varying diameter and skirt length and some have plastic tops.  These differences have to be catered for in the manufacturing of the crimping tool so a drawing or samples of the customer’s caps are important to ensure that we supply a compatible crimping tool.

If you are using spray pump caps for nasal medications or cosmetics, a multi-fingered split-collet type of crimper may be required, especially when the cap skirt is long and is therefore required to be laid against the neck of the bottle.

How well does the cap, stopper and vial fit together?

Some manufacturers supply caps which are smaller in diameter than US and European standard sizes.  They can also be short in skirt length so care should be taken before trying to mix and match as the vials and stoppers may not be a suitable fit for the assembly.  If the cap is not long enough, it won’t fit! If the diameter is wrong, it will look untidy or even jam the tool.  Sorry about that but you get my point.  The best fitting tool along with quality compatible components is the key to a secure seal and there is no substitute for a quality crimper.

We at LPL stock regular size crimpers and de-cappers along with compatible vials caps and stoppers.  We also manufacture many special crimpers and de-cappers so please contact us for details.

Ken Marshall
Director of Engineering
Laboratory Precision Ltd. ©