Positive Pressure Purge System

Tovent TYPZ/TYEA complies with GB3836. Pneumatic design purges gas before startup and maintains internal pressure for Zone 1&2 motors.

Multi-model Positive Pressure Purge for Domestic & Export Motors

Seven Tovent purge control series meet all explosion-proof demands: Exe models for Zone2 exported motors, pressurized units for Zone1 high-risk chemical equipment, low-temperature & dust special models for extreme working conditions, plus pressure alarm and emergency air supplement modules to complete system protection. All modular models support customized flow and port sizes with full bilingual drawings and test reports.

Mass deployed at domestic coal chemical and grain plants, and support ATEX/IECEx certification for exported motors to fit global explosion-proof project procurement.

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Options de personnalisation

High-Strength
Flow Rate Customization

Purge flow ranging from 700 to 6000 NL/min can be customized to match ventilation demands of small, medium and large Exe & pressurized explosion-proof motors. The purge timer is adjustable from 0 to 99 minutes. Total air volume is calculated based on motor cavity volume to comply with GB3836 standards for grain, coal chemical and other working conditions.

Quality Packaging
Material & Anti-corrosion Customization

304 or 316L stainless steel enclosures are optional. 304 for ordinary workshops, 316L for salt fog, hydrogen and corrosive sites. Low-temperature units can be equipped with heat tracing insulation for outdoor northern, chlor-alkali and fine chemical hazardous areas to extend service life.

Nontoxicity
Interface Thread Customization

PT British pipe thread and NPT American thread ports are available with customized 1″or 1/8″ female ports. Extended anti-freeze air pipes and air filter dryers are optional for domestic projects and exported European & American motors to fit on-site air pipeline standards.

Unique Design
Special Working Condition Customization

Low-temperature heat tracing, Zone21/22 dust-proof and Zone1 IIC hydrogen-resistant versions are customizable. Dust models adopt anti-static structure and double-layer flame arrestors; hydrogen versions use hydrogen-resistant seals to solve risks in powder and high-risk chemical sites.

Pressure Unit

Common pipe threads mainly include NPT, PT (ZG)(Rc), G and other types.
  1. NPT is the abbreviation of National (American) Pipe Thread. It is a 60° tapered sealed pipe thread under US standards, widely used in North America.
  2. PT (BSPT) stands for Pipe Thread. It is a 55° British tapered sealed pipe thread belonging to the Whitworth thread family, widely used in Europe and Commonwealth nations with a taper ratio of 1:16. It is domestically known as ZG or Rc.
  3. G refers to 55° non-sealed pipe thread from the Whitworth thread family. The marking G denotes parallel pipe thread.

Positive Pressure Principle

Pressurized Enclosure Type: Fresh air or inert gas with certain pressure is fed into the equipment enclosure to block surrounding flammable gas from entering, isolating ignition sources from explosive gas mixtures and preventing explosions.
Increased Safety Type: Electrical equipment that generates no arcs, sparks or high temperatures capable of igniting explosive mixtures under normal operation. Extra safety measures are implemented to avoid such hazards under normal and approved overload conditions. Per IEC and latest national standards, Exe motors require pre-purge before startup; a large volume of protective gas shall flush the motor internal cavity every time the motor restarts.

Purge System

The purge control system is mounted near or on the motor. It automatically controls protective gas to fully replace the air inside the motor cavity before startup, ensuring a safe internal environment upon motor activation.
After startup and during operation, the system continuously monitors and intelligently maintains internal motor pressure at least 150 Pa higher than ambient pressure (the national standard threshold is 50 Pa). This stops flammable and explosive gas in hazardous areas from penetrating the motor housing to achieve explosion protection.

Avantages du produit

Tovent TY series purge control systems are intelligent pressure control devices built with full pneumatic modules and multiple patented technologies, featuring prominent strengths as below:
  1. Certified by national authoritative institutes, supporting motors & electrical equipment to obtain core domestic and overseas explosion-proof certifications.
  2. Applicable to all explosion hazardous areas, guaranteeing safe and stable operation of pressurized explosion-proof electrical equipment.
  3. Full pneumatic structure without external power supply, intrinsically safe and long-lasting.
  4. Modular component design for easy maintenance and overhaul.
  5. While delivering pressurized explosion protection, it removes condensate, dust, debris and oil stains inside motor cavities for extra equipment protection.
  6. Serialized product models cut manufacturing cost and shorten production lead time for motor & electrical manufacturers.
  7. Core system parts adopt original imported components for steady and reliable performance.
  8. All series hold domestic explosion-proof certificates, CCC and other official qualification documents.

All-pneumatic TY Purge System, Intrinsically Safe Power-free Explosion-proof Purge Unit

Electric purge gear carries circuit ignition risks, while Tovent  TY all-pneumatic modules require no external power for intrinsic safety in chemical & coal-chemical high-risk zones. Modular parts enable easy disassembly and low maintenance cost, imported core components deliver stable long-term operation. The unit completes pre-purge air exchange and cavity cleaning to remove dust & condensate, maintaining safe positive pressure to block flammable mixtures. Full explosion-proof certifications support Exe & pressurized motor matching for long-term stable production in all explosion-proof workshops.

Usage Environment

The system operates reliably under the following environmental conditions:
  1. Altitude ≤2000m (Consult manufacturer if altitude exceeds 2000m);
  2. Ambient temperature range: -50℃~+55℃ for low-temperature models; -20℃~+55℃ for standard models. Ambient relative humidity ≤95% at +25℃;
  3. Zone 1/2 with flammable gas/vapor-air mixtures, or Zone 21/22 with combustible dust mixtures;
  4. Powered by protective gas: dry, clean compressed air or inert gas without flammable ingredients;
  5. Air supply pressure: 4~10 Kgf/cm². Air flow shall be 1.2 times higher than the sum of set purge flow and motor leakage flow

Motor Purge Selection Instructions

The purge air flow rate and purge duration before motor startup are usually provided by motor manufacturers as technical parameters, or can be calculated per the table below (in accordance with GB/T 3836.5-2021).
The adjustable purge time ranges from 0 to 99 minutes. Calculation can be performed based on the free internal volume of the motor housing and selected purge flow, with the formulas as follows:
Purge Flow × Purge Time = Total Air Exchange Volume
Total Air Exchange Volume ≥ 5 × Housing Volume (the sum of motor free internal space volume and rotor volume)

Product Series

We develop a full range of purge and positive pressure control products for electrical equipment deployed in hazardous industrial explosion-proof locations.

The product lineup includes Exe purge systems, pressurized purge systems, low-temperature positive pressure control systems, pressure monitoring & alarm systems, emergency bypass air supplement systems, positive pressure dust control systems and room purge systems. Standard model selections are listed in the table below:

System Category Model Flow Range Application Zone
Exe Purge System TYEA-2ZA 500-1500 NL/min Zone2
Exe Purge System TYEA-6ZA 2000-6000 NL/min Zone2
Exe Purge System TYEA-8ZA 7000-12000 NL/min Zone2
Pressurized Purge System TYPZ-1ZY 200-800 NL/min Zone1&2
Pressurized Purge System TYPZ-2ZY 500-1500 NL/min Zone1&2
Pressurized Purge System TYPZ-6ZY 2000-6000 NL/min Zone1&2
Pressurized Purge System TYPZ-8ZY 7000-12000 NL/min Zone1&2
Low-Temp Pressurized Purge System

(-50℃ ~ +55℃ Ambient)

TYPZ-2DW 500-1500 NL/min Zone1&2
Low-Temp Pressurized Purge System

(-50℃ ~ +55℃ Ambient)

TYPZ-6DW 2000-6000 NL/min Zone1&2
Low-Temp Pressurized Purge System

(-50℃ ~ +55℃ Ambient)

TYPZ-8DW 7000-12000 NL/min Zone1&2
Pressure Monitoring & Alarm System TYFD-PG 0-4000 Pa Zone1&2
Emergency Bypass Air Supplement System ACU-2000 0-2000 NL/min Zone1&2
Emergency Bypass Air Supplement System ACU-3000 0-3000 NL/min Zone1&2
Emergency Bypass Air Supplement System ACU-4000 0-4000 NL/min Zone1&2
Positive Pressure (Dust) Control System TYPZ-FC-1L 0-1000 NL/min Zone21&22
Positive Pressure (Dust) Control System TYPZ-FC-2L 0-2000 NL/min Zone21&22
Positive Pressure (Dust) Control System TYPZ-FC-3L 0-3000 NL/min Zone21&22
Compressor Nitrogen Purge System TYPZ-N2P1-3 0-1500 NL/min Zone1&2
Room Purge System TYPZ-ROP3 0-3000 m³/h Zone2
Room Purge System TYPZ-ROP5 0-5000 m³/h Zone2

Valve Accessories for Positive Pressure Purge System

Standard fitting for Ex p pressurized motors. It enters closed-loop stabilization after purging and adjusts flow against tiny seal leakage to avoid interlock shutdown. Compatible with nitrogen & dry air, customizable NPT/PT threads with optional heat tracing. No external control required. Widely used in fertilizer, salt chemical and pharmaceutical dust workshops to solve frequent shutdown caused by pressure loss.

djustable relief valve for positive purge systems with top screw to set overpressure threshold on-site, matching Exe & Exp motors. Built-in multi-layer flame arrestor monitors purge flow and releases excess pressure automatically. 304 stainless housing with downward outlet blocks dust backflow. Fully mechanical without spark risks, pressure adjustable without disassembly, universal safety fitting for chemical & coal chemical explosion-proof motors.

Self-developed TYJS-100 pneumatic timer reaches domestic leading tech level, compatible with full TYEA/TYPZ purge systems with adjustable 0–99 min timing. Air-powered without power supply eliminates spark risks and complies with GB/T3836.5 standards. It triggers timing automatically when flow meets standard and sends passive signal to interlock motor. 304 housing resists salt fog for coal & grain Zone2 motors, stable mechanical operation avoids regular calibration and safety inspection penalties.

Tovent pressure alarm system matches full TYPZ/TYEA units to collect motor differential pressure and monitor 150Pa safety threshold with adjustable dual pressure limits, sound-light alarm and interlock shutdown. With CCC explosion certificate, 316 housing fits Zone1 IIC hydrogen reactor motors, linking leakage compensator & relief valve to form closed-loop protection as standard safety device for chemical workshops.

Tovent high-precision DP sensor serves as core component for purge systems with 1Pa accuracy to track tiny cavity pressure and judge 150Pa safety value, linking timer & alarm unit for closed-loop control. 316L anti-corrosion diaphragm resists hydrogen and salt fog, intrinsically safe for Zone1 reactors. Mini structure fits compact motors with customizable PT/NPT threads and zero long-term drift, standard fitting for coal chemical and nuclear motors.

Professional Positive Purge System Manufacturer, One-Stop Supply of Full Range Explosion-Proof Equipment

Integrated R&D, production, sales & after-sales manufacturer of positive pressure equipment, supplying purge control systems, Ex cabinets, differential pressure sensors and purge valves. Self-owned workshop and test lab conduct full pressure, purge and alarm inspection for every unit. Served thousands of chemical, oil & gas manufacturers, undertake large renovation EPC, OEM & ODM available. Complete certificates provided, stable bulk supply, 24-hour after-sales support and lifelong technical upgrade service.

  • We picked this brand after comparing many suppliers. The equipment is well-built, split purge units fit outdoor cabinets perfectly and work reliably in low temperatures, with favorable bulk prices.

  • This purge unit for Zone 22 dust sites has great tightness. Standard automatic pre-purge runs unattended, preventing powder from entering cabinets and cutting our maintenance costs greatly.

  • We bought it together with explosion-proof cabinets. Full certificates including ATEX make customs and acceptance easy for overseas projects, and the custom lead time is manageable.

  • Our old purge device triggered false alarms frequently. This intelligent model rarely malfunctions, and its pressure compensation function works well for long continuous operation in dusty grain workshops.

  • Our site has limited space, and the integrated purge unit takes little room. Its interlock power-off protection is reliable, and the renovation finished fast without halting our production

How does the positive pressure outer shell prevent explosions?

Pressurized fresh air or inert gas fills the motor housing, blocking external flammable gases from getting inside. It separates potential ignition sources from explosive mixtures to avoid explosion accidents.

What features do increased safety motors have?

avoid arc, spark and high-temperature ignition sources in normal use, with enhanced structure to prevent hazard-forming faults under permitted abnormal cases. IEC and new national rules mandate pre-start purging: large protective gas flow renews all internal gas on each startup.

What does the purge control system do?

Fitted on the motor, it auto-purges the cavity pre-start for safe initial status.In operation, it stabilizes inner pressure at minimum 150Pa above ambient (50Pa national standard), stopping external flammable/explosive gases from entering the motor for consistent explosion safety.

Alternative Names:

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