Engineered to meet ISO 9001, CE, and global hazardous zone compliance standards.
In processing environments where volatile gases, vapors, or combustible dusts are present, standard electrical pressure switching instruments pose a severe ignition hazard due to electrical arcing during contact make-and-break cycles. Explosion-proof electric contact pressure gauges serve as a critical defense line, delivering simultaneous local visual pressure monitoring and automated electrical signal control (alarm, interlock, or pump start/stop) while containing any internal explosion inside a heavy-duty flameproof housing.
Unlike intrinsically safe systems (Ex ia) which limit electrical energy, an explosion-proof (flameproof Ex d) electric contact pressure gauge is constructed with an ultra-rugged die-cast aluminum or heavy-walled stainless steel enclosure. Should an explosive gas mixture enter the internal housing and detonate due to a contact spark, the enclosure withstands the internal explosion pressure without rupturing.
Furthermore, carefully calculated flame path gaps (spigot joints and threaded flameproof joints) cool the escaping hot combustion gases below the auto-ignition temperature of the surrounding atmospheric environment (such as Class I, Division 1/2 or Zone 1/2 hazardous locations).
Standard mechanical contacts often suffer from contact chattering caused by machine vibrations or pressure pulsations, leading to arcing, pitting, and signal instability. Our explosion-proof gauges utilize high-strength magnetic-assisted electric contact arms.
As the pointer moves toward the setpoint limit, a permanent magnet attached to the contact signal arm attracts the contact pin right before touch, establishing instant snap-action closure. This magnetic pull drastically suppresses electric arcing, extends contact operational life beyond 100,000 cycles, and prevents relay chatter under heavy fluid vibration.
Designed in compliance with international standards including EN 837-1, GB/T 1226, and IEC/EN 60079 series.
| Parameter | Standard Specification Range |
|---|---|
| Nominal Dial Diameters | 100 mm (4 inches), 150 mm (6 inches) |
| Accuracy Class | ±1.6% FS (Standard), ±1.0% FS (High Precision / Custom Option) |
| Pressure Ranges | -0.1...0 MPa (Vacuum) to 0...0.6 MPa, 1.6 MPa, 10 MPa, up to 100 MPa (15,000 PSI) |
| Explosion-Proof Markings | Ex d II CT6 Gb / Ex d II BT4 Gb / Ex tD A21 IP65 T80℃ |
| Contact Configurations | Upper Limit (1NO), Lower Limit (1NC), Double Upper (2NO), Upper & Lower (1NO+1NC), Double Lower (2NC) |
| Maximum Voltage / Current | AC 380V or DC 220V; Maximum Switching Power: 30VA (Contact current ≤ 1A) |
| Wetted Parts Materials | SUS316L, SUS304, PTFE/Hastelloy C Diaphragm Seals for Corrosive Media |
| Enclosure Ingress Protection | IP65 / IP66 Dust-tight & Water Jet Resistant |
| Operating Environment | Ambient: -20°C to +60°C; Media Temperature: up to +150°C (with Siphon/Cooling Tower) |
Huzhou Accuracy Instrument Co., Ltd. combines 20 years of precision manufacturing with modern automated engineering.
Our production line utilizes 100% automated laser-welded Bourdon tubes and seamless capillary joints. Every pressure gauge undergoes computer-controlled deadweight tester laser calibration across 5 distinct scale points to eliminate zero-shift and hysteresis.
From CNC precision machining of flameproof housings to custom movement assembly and diaphragm seal coating, our local Chinese supply chain ecosystem ensures short lead times, direct component sourcing, and competitive factory-direct pricing for OEM partners.
Our in-house laboratory conducts 100% pressure endurance cycling (up to 1,000,000 pressure pulses), thermal shock testing (-40°C to +80°C), and explosion-proof flame-path pressure gap validations adhering strictly to ISO 9001 and ISO 17025 testing frameworks.
Deploying reliable flameproof pressure control across critical energy, chemical, and industrial sectors worldwide.
Used extensively on offshore platforms, wellheads, crude oil pumps, and hydrocracking refineries. The Ex d II CT4 gauge automatically triggers safety shut-off valves or triggers high-pressure alarm sirens when fluid pressures breach operational safety windows.
For highly aggressive acids, solvents, or polymer fluids, our explosion-proof electric contact pressure gauges are paired with 316L SS, Hastelloy, or PTFE diaphragm seals, insulating the internal movement from clogging or chemical destruction.
In green hydrogen production, gas compression, and dispensing stations (Class I, Group B/Hydrogen environment), specialized flameproof pressure instruments prevent hydrogen embrittlement while guaranteeing rapid contact switching in explosive gas atmospheres.
Beyond explosive gases, industrial facilities dealing with coal dust, flour, or pharmaceutical powders require dust-ignition-proof protection (Ex tD). Our sealed heavy-duty housings ensure zero dust ingress, eliminating ignition risks in Zone 21 & 22 areas.
How procurement managers and systems engineering teams select the optimal explosion-proof pressure switch gauge.
Confirm whether your installation requires Zone 1 (Ex d II CT4/T6) or Zone 2 protection. Check the atmospheric gas group (IIA, IIB, or IIC for Hydrogen/Acetylene) to ensure the housing flameproof gap meets localized ATEX/IECEx or GB standard mandates.
Choose between single-contact control (Upper limit for overpressure relief; Lower limit for pump prime protection) or dual-contact control (Upper + Lower limits for automated tank level/pressure loop control between two pressure setpoints).
Select standard stainless steel Bourdon tubes for non-corrosive liquids/gases, or specify sanitary/flanged diaphragm isolators for viscous, crystallizing, or toxic media. Liquid-filled cases (Glycerin/Silicone) are available for high-vibration applications.
20 YEARS OF EXPERIENCE AND RESEARCH
Huzhou Accuracy Instrument CO LTD is professionally engaged in the development, sales and service of industrial mechanical pressure gauges, bi-metal thermometers, SF6 manometer, pressure sensor. Products are widely used in various applications such as Mechanical Engineering, Chemical Engineering, Food Industry, Pharmaceutical, and high technology electric appliances.
Established over two decades ago, our pressure gauge manufacturing facility spans 3,000 square meters, equipped with advanced production lines and rigorous quality control systems. As an industry leader, we integrate innovation with precision engineering to deliver reliable measurement solutions for global clients.
20 Specialists focused on material innovation, smart sensor integration, and compliance with international standards (e.g., ISO, API).
120 Technicians utilizing automated assembly and laser calibration technologies to ensure product durability and accuracy.
15 Professionals providing 24/7 technical support and customized solutions across 30+ countries worldwide.
Over 2 million units annually, with 100% pressure cycle tests and environmental simulations adhering to ISO 9001 and ISO 17025 standards.
We have long followed the concept of "reasonable price, accurate delivery, good quality" and several business management models to keep our production quality above the required benchmark under ISO9001:2008 certified.
Expert insights on installation, maintenance, and technical selection for explosion-proof electric contact pressure gauges.
Complete product range engineered for hydraulic, gas density, micro-fused sensing, and differential pressure control.
Accuracy Instrument