Pressure transmitters and pressure gauges can be adapted to almost any process condition using valves, protective devices and/or fittings. WIKA offers such combinations in the form of a “hook-up”, an application-specific and ready-to-install solution. It eliminates all the disadvantages that users experience with the alternative of doing the assembly themselves.
1. The logistical effort:
This is considerable. Measuring instruments, valves and other accessories, if they are brought together in-house, usually need to be sourced from different manufacturers, frequently from more than two companies. The order processes need to be coordinated, which can be time-consuming. Furthermore, supplier management requires additional resources.
2. Compatibility problems (risk of leakage):
Combinations of pressure measuring instruments with instrumentation valves and accessories are not standard solutions. Both elements of such an assembly generally come, as mentioned, from different manufacturers. This increases the likelihood of complications during assembly.
The difference in these measuring arrangements with differential pressure gauges is obvious – on the left, an example of an assembly made by the operator themselves, on the right, the hook-up solution from WIKA.
An example of this, shown here, is the combination of a differential pressure gauge with a valve manifold. The connection of the measuring instrument has a different centre distance than that of the selected valve manifold (picture left). In such a case, the connection can be achieved through an assembly with two pipe pieces and four adapters. But this solution increases the outlay in time and expense, and also the risk of leakage, by doubling the sealing points (see arrow marks). Difficulties in assembly also arise if the tolerances of the connection interfaces from different suppliers do not match exactly. This also carries the risk of leakage. In order to achieve the desired compatibility, the qualification and delivery specification must be defined for each supplier with considerable effort.
Two examples of hook-up solutions:
Left: Pressure gauge with overpressure protector, a valve to separate the measuring instrument from the process and a siphon tube that protects the complete measuring arrangement from excessive temperatures.
Right: Pressure gauge with overpressure protector and monoflange (this enables separation of measuring instrument and process in the case of flange connections).
3. The installation effort:
On top of the requirements for the procurement of suitable components, are the assembly costs for measuring points with instrumentation valves and accessories also added. These range from the development of special know-how and employee training to the provision of a suitable workplace, including tools and the necessary materials. Furthermore, a quality control is mandatory to check the functionality and reliability of the measuring arrangement, especially its leak tightness. This is especially important if, for example, it is a process with critical gases.
Avoidance of risks
With a hook-up solution, users circumvent the efforts and potential risks described here. The measuring arrangement is assembled at WIKA (on the basis of the specified process parameters and the installation situation) from qualified individual parts and is tested for leaks. It is ready for installation in the process on delivery. If necessary, a measuring instrument can also be combined with several instrumentation valves and accessories (see illustration left).
Note
Detailed information on valves and protective devices can be found on the WIKA website.