Quality, durability, and stable performance in every valve design

Minimum Pressure Valves

VMC Minimum Pressure Valve for Screw Compressors — G‑Series

The VMC G‑Series minimum pressure valves are among the most precise and reliable control components used in industrial screw compressors. Their primary function is to maintain the initial pressure inside the compressed‑air system. Until the tank or system reaches the required minimum pressure, the valve keeps the discharge line closed. This prevents oil from flowing back into the airend and ensures full safety and stability during start‑up or unloaded operation.

---

Engineering and Construction

A close look at the component shows a body manufactured from industrial‑grade anodized aluminum. The dark‑gray metallic finish accurately represents VMC’s corrosion‑resistant surface treatment. This lightweight yet robust structure is produced through precision casting and CNC machining to guarantee stable performance at pressures up to 15 bar.

The internal mechanisms use AISI 304 stainless steel for moving components and industrial brass for the flow‑control ports. The sealing elements are made from FPM/FKM compounds, providing heat resistance up to 120 °C and full compatibility with synthetic and mineral compressor oils. The embossed VMC logo on the top cover confirms the authenticity of Italian manufacturing and the G‑Series designation.

---

Model Range and Performance

The G‑Series is available in multiple sizes, from G10 ½″ to G60R, each designed for a specific capacity range:

• Small models such as G10 and G26 for compressors rated 35 to 250 CFM

• Medium models G36 and G46 for 400 to 1000 CFM units

• Large models G50T and G60R for multi‑screw systems handling up to 2100 m³/min

The valve opens at a calibrated set point of 6.5 ± 0.25 bar. Before reaching this threshold, the discharge pathway remains closed, preventing sudden pressure drops and protecting the lubrication circuit.

---

Threaded and Flanged Versions

Two main designs are available, as reflected in the product images:

• Threaded versions (Rp ½″ to Rp 2″) with compact geometry for direct mounting on the discharge line, weighing between 0.3 and 3.2 kg

• Flanged versions for high‑pressure applications, with diameters from 35 to 90 mm and bolt patterns ranging from N°4 × M17 to N°8 × M18, weighing up to 17 kg in the G60R model

All internal connection surfaces are nickel‑ and PTFE‑coated, enabling leak‑free operation even in natural‑gas (NG) or lubrication‑circuit (WL) applications.

---

Flow Technology and Pressure Control

The G‑Series incorporates two proprietary VMC engineering concepts:

• Centric Flow Channel: a central airflow path designed to eliminate turbulence during valve opening
• Thermo‑Balanced Routing: dynamic flow‑path adaptation based on thermal changes, ensuring long‑term pressure stability

These features keep operational pressure drop below 0.2 bar and maintain load/unload pressure fluctuation within 2%.

---

Appearance and Visual Details

In the product image, the dark anodized surface shows a white light reflection on the upper‑right corner — the outlet section covering the internal oil‑control channel. CNC machining lines along the housing confirm the manufacturing accuracy and assembly quality of VMC components.

At the center of the body, the “G‑Series by VMC” laser‑engraved mark provides traceable identification for testing and verification.

---

Advantages and Industrial Applications

• Maintains initial system pressure and prevents oil backflow

• Reduces mechanical shock during compressor start‑up

• Heat resistance up to +120 °C and pressure tolerance up to 15 bar

• Extremely low pressure loss with long seal life

• Fully compatible with compressors from Atlas Copco, Ceccato, ELGi, Fusheng, Hitachi, and other major brands

---

Authenticity and Supply by Iran Compressor Sadegh

All VMC G‑Series models are supplied with valid part numbers and hydrostatic test reports by Iran Compressor Sadegh. Each valve undergoes leak and pressure testing between 6 and 10 bar before delivery, and an official VMC authenticity certificate is issued to the buyer.

---

Technical Summary

For maintaining initial pressure, reducing airend wear, and achieving precise control in screw‑compressor operation, the VMC G‑Series minimum pressure valves are among the best in their class — combining mechanical durability, European engineering, and dependable performance for heavy industrial applications.

Parts and Related Equipment Gallery