Making a connection
Tom Shelley reports on an easy to use device for connecting and disconnecting sensing loops to high pressure fluid lines
A connection system developed for the oil and gas industry is finding use across a range of high pressure fluid systems.
PhastFit can quickly connect and disconnect differential pressure transmitters across orifice plates in high pressure process lines. It forms an essential part of Parker Instrumentation's Close Coupled Instrument Mounting Solution (CCIMS).
"The costs of mounting differential pressure transmitters has stayed much the same for decades and are unquestioned by plant owners," said Brian Rice, market development manager of Parker. "We have worked with transmitter manufacturers and users to develop this concept."
It replaces what are usually hand crafted assemblies of 20 or more items - pieces of tubing, joints, valve components and brackets that can take anything from one to three man days to make up. Parker says that the CCIMS can be installed in less than half an hour - at a pre-launch demonstration a non-expert took eight minutes - and disconnections and instrument swaps can be made in only a few seconds. It also shortens the paths between pipe and instrument, which improves response and reduces opportunities for blockages. By reducing the number of joints, it cuts the opportunity for leakage.
The system is made up of two main parts: a pipe interface module with isolation valves, which connects to holes drilled in flanges on each side of the orifice plate; and an instrument mounting module. The pipe interface module includes one ball and one sleeve connector to accommodate various types of misalignment problems associated with the flanges. But the clever part is the interface with the instrument mounting module. Disconnection requires use of a special tool that cannot be inserted unless both isolation valves are closed. Once the instrument mounting module has been removed, the valves cannot be opened. An emerging spigot on the pipe interface module must be pressed down by the presence of the instrument mounting module in order for the valves to open. When the instrumentation module is removed, it is also possible to padlock the spigot in the extended position to make doubly sure the valves are not opened.
When re-attaching the instrument mounting module, the tool allows the seals to be compressed without having to apply large amounts of force to the instrument mounting module. The shape at the end of the tool cannot be imitated using screwdrivers or other pieces of metal, which prevents module removal by unauthorised people.
"CCIMS allows the industry to re-engineer instrument mounting practice, to save cost and enhance performance," said Rice.
Parker CCIMS system
Pointers
* Pipe interface module has ball and sleeve connections to accommodate flange misalignment
* The instrument mounting module is attached by a click and lock mechanism using a special tool - and can only be done with the isolation valves closed. These remain locked in the closed position after removal
* Installation time for the whole system is typically less than half an hour. Instrumentation mounting modules can be removed and replaced in a few seconds