Product Catalogue and Diaphragm Seal Systems

Catalogue 2nd Edition Thank you for considering PCI Instruments for your instrumentation needs. Our catalogue provides an overview of our products and the services we can offer. If you require more detailed information or technical data sheets, they can be found on our website at www.pci-instruments.com About Us Founded in Southport, United Kingdom, PCI Instruments Ltd has grown to become a leading and recognised British manufacturer of process instrumentation. Our products include pressure gauges, temperature gauges, diaphragm seals, transmitters, RTD Pt100’s, thermocouples, thermowells and...

Instruments with Diaphragm Seals Page 2 Diaphragm Seal Filling Page 4 Fit and Fill Service for Seals Page 6 Diaphragm Seal Manufacturing Page 8 Hygienic Diaphragm Seals Page 10 Flanged Diaphragm Seals Page 14 Chemical Diaphragm Seals Page 18 Diaphragm Seal Gauge Manufacturing Page 22 Diaphragm Seal Gauges Page 24 Pressure and Vacuum Gauges Page 26 Pressure and Temperature Transmitters Page 35 Temperature Gauge Manufacturing Page 38 Temperature Gauges Page 39 Digital Thermometer Manufacturing Page 40 Digital Thermometers Page 41 Temperature Probes Page 46 Flushing Rings Page 49 Tank Level Gauges...

‘Quality Matters’ Pressure Instruments with Diaphragm Seals A diaphragm seal’s main purpose is to protect the pressure instrument from the process medium. Diaphragm seals are normally connected directly to the instrument but connection may be made by a capillary. The air space behind the diaphragm membrane and inside the instrument is filled with a fill fluid which acts as a hydraulic medium. When pressure is applied to the diaphragm membrane it is hydraulically transmitted to the instrument’s sensing element by the displaced fill fluid. This allows the instrument to measure the process pressure...

‘Quality Matters’ Some circumstances when a diaphragm seal may be used • Process medium is corrosive The process medium would chemically attack the working parts of a pressure instrument. • Process medium is viscous or contains solid particles The process medium could block the instruments pressure inlet preventing any pressure from reaching the measuring element. • Process medium is sterile It is important to eliminate dead spaces which are inaccessible for cleaning and provide a site where bacteria can develop. • Process medium is very hot or cold The process medium is at such a temperature...

‘Quality Matters’ Diaphragm Seal Filling Some of the challenges of producing an accurate and stable diaphragm seal system is linked to the effect temperature has on liquids. The diaphragm seal system relies on a fill fluid to hydraulically transmit the pressure applied from the diaphragm membrane to the instrument’s measuring element. Fill fluids being liquids, will expand or contract when affected by ambient and process temperature (or full vacuum). The fluctuation in fill fluid volume can affect the internal force applied to the instrument’s measuring element. Which in turn can result in pressure...

‘Quality Matters’ Diaphragm Size Another factor to be considered is the choice of diaphragm membrane size. Smaller diaphragm membranes are very rigid. Any fill fluid expansion or contraction has little effect on a rigid diaphragm but instead acts upon the measuring element inside the instrument resulting in errors and zero shifts. However a suitably larger diaphragm membrane is more flexible and can absorb some expansion preventing a zero shift. Additionally the larger surface area of a large diaphragm means less force is required to act upon the measuring element allowing for better measurement...

‘Quality Matters’ Fit and Fill Service for Seals We provide a fit and fill service with our diaphragm seals. Many leading pressure transmitter companies free issue their instruments to have a PCI diaphragm seal fitted. Our charge for this service is competitive and we offer a fast turn around time. This is often crucial for the end client. We can fit all manufacturer’s instruments to a diaphragm seal Your Gauge Your Switch Your Transmitter For further information call +44 (0)1704 509090

‘Quality Matters’ Leading transmitter brands fitted with PCI diaphragm seals Welded Construction Protective Packaging View our product datasheets at www.pci-instruments.com

‘Quality Matters’ Diaphragm Seal Manufacturing PCI manufacture a wide range of diaphragm seals for hygienic and chemical applications. Our diaphragm seals are made to suit the pressure sensing instrument and the application. Our most common diaphragm seals are made from stainless steel grade 316L which is the standard material for the pharmaceutical industry. Using our own CNC lathes combined with computer controlled welding equipment enables us to produce the highest quality diaphragm seals. PCI’s diaphragm seals are manufactured in the United Kingdom Leak Testing -10 All our diaphragm seals...

‘Quality Matters’ Exotic Metal Diaphragm Seals We manufacture exotic metal diaphragm seals. Exotic metal diaphragms are often required for aggressive applications were stainless steel would not be suitable. Using a specialist CNC welding process, we can weld exotic metal diaphragms such as Tantalum to a stainless steel body. This is far more economic than producing the full flange body in exotic material. These are often required within the Nuclear, Oil+Gas and Chemical industries. Examples of exotic metals include Tantalum, Titanium, Hastelloy, Inconel and Monel. We also offer special diaphragm...

‘Quality Matters’ Hygienic Diaphragm Seals Sizing guide available on page 70 TRI-CLAMP SEAL • Material stainless steel AISI316 • Suitable pressures dependant on size and clamp type used • Various sizes available VARIVENT® TYPE SEAL • Material stainless steel AISI316 • Suitable pressures -1 to 25 bar • Various sizes available DIN FEMALE SEAL • Material stainless steel AISI316 • Suitable pressures sizes -1 to 40 bar • Various sizes available For further information call +44 (0)1704 509090