Danfoss PM1-32 Pilot-Operated Main Valve

(For refrigeration systems only)

1. Model Number Breakdown

2. Core Technical Specifications

3. Principales fonctionnalités
4. Pilot-Operated Principle

Main valve operation is fully driven by control pressure from the pilot valve; no built-in actuator

Can be combined with various Danfoss pilot valves (par ex., CVP pressure pilots, TVP temperature pilots, PML solenoid pilots) for multifunctional control

Full-stroke design with minimum opening pressure differential of only 0.2 bar g, ensuring stable operation at low loads

2. Structure & Fiabilité

Externally coated with ICS 25-150 zinc-chromium coating for enhanced corrosion resistance

Internal seals use refrigerant-resistant materials for long-term leak-free operation

Can be mounted horizontally or vertically for flexible installation

3. Control Accuracy

V-shaped regulating cone for optimum control accuracy under partial load

Fast response; pressure fluctuation controlled within ±0.1 bar

Enables precise pressure and temperature control to maintain stable system operation

4. Applications typiques
5. Refrigeration System Functions

High-side pressure control (condenser pressure regulation)

Low-side pressure control (evaporator pressure regulation)

Wet/dry suction line regulation to prevent compressor liquid slugging

Liquid line regulation (under non-phase-change conditions)

2. Industrial Fields

Food and beverage freezing and cold storage systems

Low-temperature processes in chemical and pharmaceutical industries

Central air conditioning for large commercial buildings

Industrial chiller control

5. Installation & Selection Guidelines
6. Exigences d'installation

Vertical installation recommended with pilot port facing upward for easy maintenance and venting

Thoroughly clean piping before installation to prevent contaminants from entering the valve body and damaging seals

Use standard-compliant bolts and gaskets for flanged connections, tightened to specified torque

2. Selection Principles

Select appropriate size based on maximum system flow; PM1-32 is designed for medium flow requirements

Consider system working pressure and temperature to ensure operation within rated limits

Choose matching pilot valve type (pressure/temperature/solenoid) to achieve desired control function

3. Maintenance Notes

Regularly inspect pilot port seals to prevent refrigerant leakage

Check valve operability before restart after long shutdown

For low-temperature applications (-50°C to -60°C), replace bolts with A4-80 stainless steel

6. Modèles de remplacement & Cross-Brand Comparison

6.1 Danfoss Internal Replacements

6.2 Cross-Brand Equivalents

7. Functional Expansion & Combined Applications

The PM1-32 can achieve multiple control functions when combined with different types of pilot valves:

1. Pressure control: Combined with CVP constant pressure pilots to maintain stable system pressure
2. Temperature control: Combined with TVP temperature pilots to regulate flow based on temperature signals
3. On-off control: Combined with PML solenoid pilots for fast switching of refrigerant circuits
4. Complex control: Multiple pilot valves connected via external piping for multifunctional composite control

The Danfoss PM1-32 is a high-performance, high-reliability pilot-operated main valve specifically designed for DN32 refrigeration systems, delivering precise pressure and temperature control. Its single pilot port and compact structure make it widely used in small-to-medium industrial refrigeration systems, especially in food freezing, chemical cooling, and other applications requiring stable control. By combining with various pilot valves, it can flexibly realize multiple control functions to meet diverse application needs.

Below is a ready-to-use engineering selection version compiled according to official Danfoss specifications:

Complete PM1 series model list + key differences between PM1 / PM3 + pilot valve selection table.

1. Complete Model List: Danfoss PM1 Series (Refrigeration Main Valves)

PM1 is a single pilot port pilot-operated main valve, flanged, PN16 / PN25, for general refrigeration systems.

General Specifications (consistent across the series)

Max working pressure: 28 bar

Temperature range: -60℃ ~ +120℃

Body material: GGG40.3 ductile iron

Approved refrigerants: HFC / HCFC / NH₃ / CO₂

Montage: horizontal or vertical

2. Key Differences Between PM1 and PM3 Series

Direct comparison to avoid selection confusion:

Simple rule:

Only one control signal → choose PM1

Pressure + temperature control required → choose PM3

3. Pilot Valve Selection for PM1-32 (Most Common Combinations)

The PM1 main valve has no control function on its own and must be used with a pilot valve.

Below are the most frequently used pilot valves for PM1-32:

1) CVP Series Pressure Pilot Valves (Condenser / Evaporator Pressure Control)

Combination: PM1-32 + CVP10 → Most common condenser pressure regulating valve

2) TVP Series Temperature Pilot Valves (Superheat / Temperature Control)

3) PML Series Solenoid Pilot Valves (On-Off Control)

4) MBV Series Differential Pressure Bypass Pilots

MBV 1 … 10 bar

Commonly used for: compressor differential pressure bypass, anti-surge control

4. Additional Key Parameters for PM1-32 (Engineering Installation)

Minimum opening pressure differential: 0.2 bar

Flange standard: DANS 1092-1 PN16 / PN25

Seal material: NBR (standard) / HNBR (ammonia / haute température)

Poids: PM1-32 ≈ 4.0 kg

Flow direction: marked with arrow on body; non-reversible

5. Functional Equivalent Models (Cross-Brand)

Complete Range of Danfoss Refrigeration System Valves

Danfoss offers a full line of valves for refrigeration systems, covering applications from residential air conditioning to large-scale industrial refrigeration. Below is a detailed functional classification including core models, technical features, and applications for engineering selection and system design.

1. Expansion Valves (Core Throttling Elements)

Expansion valves are the “heart” of refrigeration systems, responsible for throttling, pressure reduction, and flow control. They fall into two main categories: Thermostatic Expansion Valves (TXV) and Electronic Expansion Valves (EEV).

1.1 Thermostatic Expansion Valve (TXV) Série

Avantages principaux:

Precise superheat control for efficient evaporator operation

Compatible with a wide range of refrigerants (HCFC, HFC, natural refrigerants)

Some models support bi-directional flow, simplifying heat pump system design

1.2 Electronic Expansion Valve (EEV) Série

Avantages principaux:

Precise flow regulation across full operating conditions, improving system efficiency by 10–15%

Fast response, ideal for inverter-driven and complex control systems

Enables multi-parameter control including superheat, température, and pressure

2. Solenoid Valves (System On-Off Control)

Solenoid valves provide fast on-off control of refrigerant circuits, available in direct-acting and pilot-operated versions.

2.1 General-Purpose Solenoid Valves

2.2 Special-Application Solenoid Valves

EVS: Safety solenoid valves for hazardous environments

EVM: Miniature solenoid valves for small refrigeration equipment

EVRM: Manual reset type for critical safety circuits

3. Pilot-Operated Main Valves (Core Pressure / Temperature Control)

Pilot-operated main valves are driven by control pressure from pilot valves to achieve high-precision pressure or temperature regulation. They are available in single pilot port (PM1) and dual pilot port (PM3) série.

3.1 PM Series Main Valves

3.2 Matching Pilot Valve Series

4. Manuel / Multi-Function Industrial Valves (System Operation & Entretien)

The Danfoss SVL Flexline™ series is the “all-rounder” of industrial refrigeration, featuring modular design with five interchangeable function modules sharing the same valve body.

4.1 SVL Flexline™ Multi-Function Valves

Avantages principaux:

Modular design reduces inventory cost and enables flexible installation

Sizes DN15~DN100, working pressure up to 140 bar

Externally coated with ICS 25-150 zinc-chromium coating for excellent corrosion resistance

5. Sécurité & Protection Valves (System Safety Assurance)

5.1 Safety Valve Series

5.2 Check Valve Series

6. Special-Function Valves (System Optimization & Expansion)

6.1 Reversing Valves (Four-Way)

6.2 Hot Gas Bypass Valves

6.3 Valves for Transcritical CO₂ Systems

7. Danfoss Valve Selection Guide

7.1 Selection by System Type

7.2 Key Selection Parameters

1. Refrigerant type: Confirm compatibility with R410A/R32/R717/R744 etc.
2. Working pressure: Select valve with rated pressure ≥ maximum system pressure
3. Temperature range: Choose valves suitable for system min/max temperatures
4. Flow requirement: Calculate using Kv value to ensure sufficient flow capacity
5. Installation: Consider flanged / threaded / welded connections and space constraints

Danfoss refrigeration valves are known for high reliability, contrôle précis, et une large compatibilité, covering the full process of refrigeration systems: throttling, contrôle, safety, and maintenance. From miniature residential air conditioners to large industrial CO₂ refrigeration systems, Danfoss provides matched valve solutions.

Selection should be based on system type, refrigerant, operating parameters, and control requirements, referring to official Danfoss catalogs or technical support to ensure efficient and stable system operation.