Internal leak tightness

EMICOgauge

The EMICOgauge pressure measuring system, an instrument hook-up of pressure gauge and instrumentation valve, minimises the number of leak points. This reduces the risk of media escaping into the environment. The system's 360° swivel connection enables quick gauge alignment during assembly with simultaneous pressure sealing. Maintenance and dismounting of the measuring instrument and valve are also unproblematic. WIKA can guarantee the leak tightness of the assembly even after up to 20 assembly and disassembly processes.

The EMICOgauge instrument hook-up combines the model 232.34, 233.34 pressure gauge in safety version level S3 with the valve models IV10, IV11, IV2 or IVM. This results in a variety of combinations. A large variety of pressure connections is also available for the system, so that the adapters that would otherwise be required are avoided. This eliminates two further sealing points with their corresponding risk of leakage.

Valves against fugitive emissions

WIKA offers needle valves, ball valves, valve manifolds and monoflanges in a design to avoid fugitive emissions in accordance with the international standard EN ISO 15848-1 and TA Luft. Their upper bodies have the corresponding safety-relevant features: a blow-out proof valve spindle, a non-rotating spindle tip with a metal seat (low-wear operation) and a low torque for smooth and precise valve adjustment even at high pressures. In addition, there is a special seal packing made of RTFE, a reinforced PTFE. The valves are supplied with an orange ring on the bonnet and are thus clearly identifiable. They are approved by an independent authority (third party) in accordance with the standard.

Pressure sensors/Transmitters with full welded measuring cell

Electronic pressure sensors can use different kinds of sensing elements. However, each additional internal sealing structure increases the potential for fugitive emissions. To minimise this risk, WIKA welds the pressure sensor elements directly to the pressure connections, both made of stainless steel. This significantly increases the leak tightness. For specific media like hydrogen additional helium leakage tests are applied during production to ensure the correct weld.

Diaphragm seal system with diaphragm monitoring

WIKA diaphragm seal systems with integrated diaphragm monitoring currently offer the most effective protection against an undetected diaphragm rupture. You not only prevent possible environmental contamination, but also contamination of the medium by the transmission fluid.

The control function of the patented measuring system is based on a welded and evacuated double diaphragm. If the diaphragm on the process side is damaged, the vacuum is released and the monitoring unit provides information about the condition of the outer diaphragm. The internal diaphragm, meanwhile, keeps the process closed and reliably continues the pressure measurement until the damage has been repaired.

Thermowells from a single piece

One-piece bar stock material thermowells for thermometers, threaded or for welding or with flange connection, have a significantly lower emission potential than multi-piece tube designs. If variants from austenitic stainless steels such as 1.4571 or 316L could have corrosion problems, optimised versions with special materials are available. For thermowells with a flange as the process connection, the TW30 Vanstone design with a separate slip-on flange or the TW10-W version made of a forging blank are the first choice, as there are no weld seams. For variants with a welded flange, the TW10-F (FPW = Full Penetration Welding) full penetration weld design is preferable to all other welded connections for most applications.

Secondary containment

For critical applications where toxic media can escape in the event of damage to the process-side seal (weld seam or soldered joint), special design solutions are available for electrical thermometers. These have been used successfully for many years.

In the case of high-temperature thermocouples (models TC83 Calitum® and TC84), this is ensured by a double seal built into the special neck tube. If the protection tube is damaged, e.g. by falling slag during operation, leakage is contained, preventing contamination to the environment.

Multipoint assemblies for reactors (model TC96-R Flex-R®) utilize a special neck designed with a secondary containment chamber. This prevents the process medium from escaping in the event of damage to the process-side welded connection. In addition, this secondary containment is designed to be used with pressure monitoring devices, e.g. pressure gauges, vales, pressure transmitters, etc. With those devices, continuous monitoring for a primary boundary breach is achieved.