History
The original quick release connectors, used with early Self Boring Pressuremeters
were intended for use up to 400psi (2.8MPa). As maximum pressures increased,
firstly to 4MPa and then to 10MPa, a larger connector with a higher rating
was chosen. This larger one is rated to 20MPa/200 bars, but unfortunately
there is an almost identical connector that is only rated to 3.5MPa. Some
of these may have been supplied by us in the past, in place of the correct
ones.
Technical details
All the connectors involved are manufactured by a Swedish firm called CEJN.
The original small ones are the Series 220, the larger are Series 320 or
322, and it is here that the error has occurred.
The correct part numbers are:
10 - 322 - 1202 for the female connector with 1/4 BSP female thread
10 - 322 - 5202 for the male (or nipple) with 1/4 BSP female thread
alternatively 10 - 320 - 5202 for the male (or nipple) with 1/4 BSP female
thread
The female couplings have the full part number and pressure rating marked, but the males only quote 322-5202 or 320 – 5202.
The lower rated nipples are:
10 - 321 - 5202
The difference is that these are made from chrome plated brass and are polished. The correct ones are made from nickel plated steel , hardened and have a dullish surface. There is, as far as we know, no problem with the female couplings.
Action
All nipples should be inspected carefully and replaced as necessary. Although
there are certain applications, such as the membrane fitting equipment, where
the lower rated nipples are perfectly adequate; the safest thing to do is
replace all of the brass nipples with the hardened steel ones.
This advice last revised 01 May 2003