Control-room corrosion protection depends on treated intake air, room pressure, recirculation, gas-specific media and monitoring working together. One chemical filter cannot compensate for uncontrolled infiltration.
Design petrochemical and industrial electronics protection using YONGFAN PSA (850–34,000 m³/h) and PSA-PG (1,700–68,000 m³/h) fresh-air units, DBS corridor units, CA recirculation purifiers with MediaPAK PK-12 modules, motorized airtight intake dampers (<=1.2 m³/(m²·h) leakage), outdoor gas detector interlocks, and copper/silver reactivity monitoring.
Supplying chemical filtered air without maintaining positive room pressure allows untreated H2S to seep in through doors and cable penetrations.
Relying solely on fresh air units leaves internal gas spikes (from door openings or maintenance) lingering inside the room for hours.
Failing to interlock fresh-air intakes with outdoor gas detectors draws hazardous gas clouds directly into the ventilation system during plant leaks.
Monitoring only filter ΔP (which tracks dust loading) gives no indication of chemical media saturation and gas breakthrough.
Standard fresh-air corrosion-protection platform (850–34,000 m³/h, 99.5% gas removal efficiency, ISA S71.04 Class G1 target, 2,000 Pa casing rating, <1% leakage at 1,000 Pa). Aluminum alloy frame with 30 mm PU insulated panels. Filtration train: G4 pre-filter + PK12-PCB (KOH) & PK12-CPB (KMnO4) chemical stages + F8 final particulate filter.
High-capacity treated intake platform delivering up to twice the airflow of standard PSA (1,700–68,000 m³/h, 0.75–37 kW, 380 V 50 Hz, 2,000 Pa casing rating, <1% leakage at 1,000 Pa). Consolidates large fresh-air demand into fewer high-capacity skids to reduce duct branches and maintenance points.
Engineered for indoor corridor or equipment room installation. Operates in positive-pressure fresh air supply mode or room recirculation mode. Features G4 pre-filter + loose chemical media with a top-fill / bottom-discharge design for rapid on-site media replacement + F8 final filter (249 Pa ESP).
Self-contained indoor recirculation purifier (850–6,800 m³/h across 500V, 1000V, 2000V, 4000V models) with built-in VFD, LCD control, and sound-treated fan (<65 dB). Utilizes rail-mounted MediaPAK PK-12 slide-in modules for clean, fast replacement without handling loose media.
Low-leakage motorized isolation valves installed in the outdoor air intake. Features EPDM blade seals and insulated construction to prevent ambient air ingress when the unit stops. Leakage rate not greater than 1.2 m³/(m²·h) at 2,000 Pa differential pressure (AC/DC 24 V or AC 220 V actuator).
Integrates combustible and toxic gas detectors at the outdoor fresh-air intake. Upon detecting gas concentrations above safety thresholds, the controller immediately commands the motorized airtight valve to close and shuts down the PSA intake fan, preventing gas ingress into the control room.
Verifies environmental corrosion severity around sensitive electronic hardware. Includes passive copper and silver reactivity coupons (reporting corrosion film thickness in Å/month) and real-time online corrosion monitors with continuous 4–20 mA / RS-485 outputs to DCS/BMS.
| Requirement | Recommended First Route | Documented Boundary | Main Selection Input |
|---|---|---|---|
| Standard treated fresh-air intake | PSA | 850–34,000 m³/h · ISA G1 target | Fresh-air volume & gas analysis |
| High-volume treated intake for large halls | PSA-PG | 1,700–68,000 m³/h per unit | Fresh-air volume & redundancy |
| Local positive pressure or corridor duty | DBS | Function documented; project sized | Installation mode & gas load |
| Dedicated quiet room air recirculation | CA | 850–6,800 m³/h · MediaPAK | Room volume & air-change target |
| Intake isolation on unit shutdown | Airtight Damper | ≤1.2 m³/(m²·h) @ 2,000 Pa | Duct size & actuator voltage |
| Emergency intake cutoff during gas leak | Gas Detector Interlock | LEL / Toxic sensor interface | Safety shutdown philosophy |
| Verify environmental corrosion rate | Cu/Ag Coupons & Monitors | ISA S71.04 Class G1 benchmark | Monitoring points & BMS output |
Provide room L×W×H, number of rooms, door opening patterns, and target positive pressure (e.g. 25–50 Pa).
List target gases (H2S, SO2, Cl2, NOx, VOCs), normal/peak concentrations, and target ISA S71.04 Class G1.
Select PSA / PSA-PG for fresh air intake, and CA / DBS for continuous room recirculation cleaning.
Specify motorized airtight intake dampers, outdoor gas detector interlocks, and copper/silver coupons.
YONGFAN chemical engineers will calculate fresh-air pressurization rates, size PK12-PCB/CPB media beds, verify casing leakage, and supply certified submittals.
PSA and PSA-PG double-skin housings are pressure-tested to 2,000 Pa with certified leakage <1% at 1,000 Pa.
CA guide rails and MediaPAK modules are bench-tested for airtight edge sealing and smooth slide-in alignment.
Centrifugal and plug fan assemblies are verified for airflow against loaded chemical media resistance.
CA indoor purifiers are sound-tested in anechoic chambers to verify quiet operation below <65 dB(A).
Both are fresh-air corrosion-control units. PSA covers 850–34,000 m³/h. PSA-PG covers 1,700–68,000 m³/h and is designed for large control complexes.
Use DBS for indoor/corridor installation where localized positive pressure or recirculation is needed without a large external fresh-air duct run.
CA is purpose-built as an indoor recirculation purifier with sound-treated housing (<65 dB), built-in VFD, and slide-in MediaPAK PK-12 modules.
No. CA only recirculates and cleans indoor air. Positive pressure requires treated outdoor air from a PSA or DBS unit exceeding room leakage.
KOH-impregnated PK12-PCB targets H2S, SO2, Cl2, and VOCs; permanganate-based PK12-CPB targets NOx, formaldehyde, and organic acids.
The control system immediately closes the motorized airtight intake damper and stops the PSA unit, preventing toxic/combustible gas ingress.
No. That rating applies to the chemical-filtration unit casing at 1,000 Pa. Room leakage depends on doors, walls, and cable penetrations.
Deploy copper and silver reactivity coupons or real-time online corrosion monitors inside representative DCS rack areas.
No. 1–2 years are typical reference values. Actual media life depends on gas concentration, airflow, humidity, and operating hours.
No. Chemical filtration removes corrosive molecular gases; precision HVAC units provide temperature and relative humidity regulation.
ISA S71.04 Class G1 is a complete room condition; a chemical filtration unit cannot overcome unsealed doors or uncontrolled air infiltration.
Standard volume dampers leak under wind pressure; specify motorized insulated airtight dampers with ≤1.2 m³/(m²·h) leakage rating.
Blast valves and fire dampers in intake walls belong to the building blast and fire strategy; they are not part of the filtration unit.
Outdoor gas-detector interlocks provide functional equipment shutdown; verify project-specific SIL or emergency-shutdown (ESD) requirements.
Send your control room dimensions, target gases, fresh-air pressurization rates, and monitoring requirements. YONGFAN chemical filtration engineers will design an integrated G1-compliant protection system.
