Pressure reducing station - PREsys S | ARI

ARI-PREsys®-S – Steam Pressure Reduction Station

The ARI-PREsys®-S is a pre-assembled pressure reduction station for steam networks, designed to adjust from a higher inlet pressure P1 to a lower operating pressure P2. It can be configured as a standalone direct-acting unit or with electropneumatic control via transmitter, PID controller, and positioner.

Technical Configuration

• Nominal Sizes: DN15 to DN100
• Kvs: 3.2 to 125 m³/h
• P2 Ranges: 0.2–0.6 / 0.5–1.2 / 0.8–2.5 / 2–5 / 4.5–10 / 8–16 bar(g)
• Flanged Connections: PN16, PN25, PN40
• Piping Materials: P235GH or 1.4571 / 1.4541
• Valve Materials: EN-JL1040, EN-JS1049, 1.0619+N, 1.4408
• Pressure-Temperature Limits per DIN EN 1092-1/-2, by material and PN.

Versions

PRS-S: basic configuration for steam.
PRS-S Plus: with condensate drainage on P1 side.
PRS-S Complete: with bypass, steam dryer, P1/P2 drainages, and full field instruments.
Duplex: dual reduction line for installations requiring operational redundancy.

Station Equipment

The standard setup may include ARI-PREDU pressure reducer, ARI-SAFE safety valve, ARI-FABA-Plus isolation valves, Y-filter, P1/P2 manometers, ARI-CONA steam traps, visual flow indicators, bypass, and stainless steel bellows for sealing maintenance reduction.

Applications

Used in steam substations, heat exchangers, industrial process lines, steam HVAC, CIP/SIP cleaning, and supply to consumers requiring stable P2 pressure.

Selection Criteria

Proper sizing requires: medium, P1, P2, temperature, flow rate kg/h or kW, maximum possible flow, available space, required bypass, condensate drainage, and material class. The safety valve must be calculated based on maximum possible flow, not just normal operating load.

FAQ

When is electropneumatic control selected?
When tighter P2 regulation, remote setpoint, or integration into an automation system is required.

Why is a filter needed before the reducer?
To protect the seat, disc, and control line from particles that can cause leakage or regulation instability.