The Diaphragm Pressure Gauge

Chemicals, pharmaceuticals, and wastewater treatment plants face a common challenge. The media being measured are often highly corrosive, viscous, or prone to crystallization. These fluids destroy ordinary pressure gauges quickly. The spring tube corrodes. The pressure port becomes blocked. The gauge fails completely. Anhui Tiankang's diaphragm pressure gauge (YM series) solves this problem with an elegant isolation design. The gauge consists of two parts: a standard pressure gauge head and a diaphragm isolator. A closed system between them contains silicone oil or glycerin as the pressure-transmitting fluid. The measured media never enter the gauge head. They only contact the diaphragm.

Pressure transfers through the diaphragm's deformation and the isolation fluid to the spring tube. This isolation design fundamentally solves corrosion, blockage, and crystallization problems. The diaphragm pressure gauge works reliably where ordinary gauges would fail within days or weeks. Plant operators can trust the readings for months and years without constant maintenance or replacement.

The diaphragm pressure gauge offers exceptional material selection for the diaphragm. 316L stainless steel is the most common and versatile option. It handles weak acids, seawater, chlorine-containing media, and food-grade fluids. This is the standard choice for chemical water treatment and export projects. Hastelloy C-276 resists concentrated hydrochloric acid, sulfuric acid, and nitric acid. It suits fine chemical plants and acid pickling lines. Monel 400 works specifically with hydrofluoric acid and alkaline solutions. For almost all strong acids and bases, tantalum (Ta) delivers excellent performance. PTFE tetrafluoroethylene lining resists nearly all chemicals. It is a highly cost-effective "universal corrosion protection" solution.

The isolator installation structure comes in four standard forms. The threaded type (ML) suits small pipelines and atmospheric pressure equipment. It connects directly through M20×1.5 or NPT1/2 threads. Installation and removal are quick and simple. The flange type (MF) is the standard for chemical storage tanks and reactors. We supply DN25 to DN50 flanges according to HG20592 (Chinese standard) or ANSI B16.5 (American standard).
The hygienic clamp type (MC) serves pharmaceutical and food industry applications. It uses ISO2852 standard clamp connections. The diaphragm has a mirror-polished surface (Ra≤0.8μm). There are no dead corners. The design supports CIP/SIP online cleaning and sterilization. When media temperatures exceed 100°C, we offer an extended cooling type diaphragm. This prevents high temperatures from expanding the isolation fluid and affecting measurement accuracy.

All diaphragm pressure gauges strictly follow JB/T 8624 and EN 837-3 standards. Accuracy is 1.6% as standard. Export orders can be customized to 1.0% precision grade. Dial sizes include φ60, φ100, and φ150. Pressure ranges cover from -0.1MPa vacuum to 0-40MPa positive pressure.
Every diaphragm pressure gauge undergoes seal integrity testing and filling fluid inspection before shipment. Export shipments include EN10204 3.1B material certificates (specifying diaphragm material), ISO17025 calibration reports, and CE (PED) certification.