Altecnic / Caleffi 527 Series Safety Relief Valve 3/4" x 1" F x F 6 Bar - 527560EST

NABIC 568 Anti-Vacuum Valves are essential for safeguarding drying cylinders, calorifiers, and tankers against collapse caused by internal vacuum conditions. These valves are equally valuable in steam systems, where they facilitate effective condensate drainage and prevent the unwanted suction of contents from vats. Typically, vacuum valves are installed vertically at the top of the vessel or pipeline they protect. In the case of horizontal revolving cylinders, a NABIC 568 valve should be fitted at each end, positioned directly opposite each other. Our NABIC Valves are backed by an industry-leading 5-Year Guarantee for your peace of mind.

**Specifications**

• **Sizes:** 1/2", 3/4", 1", 1.1/4", 1.1/2", 2"
• **Connections:** Male BSPT
• **Materials:** Available in Gunmetal (568) or Stainless Steel (568SS)
• **Maximum System Pressure:** 13.5 Barg
• **Vacuum Set Pressure:** Pre-set to activate at a Vacuum Pressure of 50 mBarg
• **Temperature Range:** -20°C to 195°C Max

Ensure the integrity of your systems with NABIC 568 Anti-Vacuum Valves—designed for durability and reliability in demanding applications.

**Product Specification** **Sizes Available:** 6", 8", 10", 12", 14" **Connections:** Flanged DIN or ANSI **Materials:** Carbon Steel (7.1) or Stainless Steel (7.2) **Disk Material:** Viton **Joints & Seals:** **Medium Compatibility:** Non-toxic steam and gases **Set Pressure Range:** 0.4 to 0.88 Barg (depending on size) **Temperature Range:** - Carbon Steel (7.1): -10 to +130°C - Stainless Steel (7.2): -60 to +130°C **Design Notes:** This product is designed to accommodate various applications, providing reliable performance under specific conditions. Ensure to choose the appropriate size and material for optimal results. Perfect for various industries requiring safe handling of non-toxic steam and gases.

We offer pilot-operated safety valves from renowned manufacturers. Please reach out to us with your specific requirements.

A pilot-operated safety valve (POSV) is a specialised pressure relief valve that utilises system pressure, through a smaller auxiliary valve known as the pilot, to regulate the opening and closing of the main valve. These valves are predominantly used in systems where precise pressure control and effective sealing are essential, especially under high-pressure conditions.

How It Works:

• The pilot valve continuously monitors system pressure and manages the main valve's operation.
• When pressure remains within safe limits, the pilot valve keeps the main valve closed by maintaining pressure on the upper side of the valve piston or diaphragm.
• If the pressure surpasses the predetermined limit, the pilot valve opens, allowing pressure to vent from above the piston, resulting in the main valve fully opening to relieve the pressure.
• Once the system pressure falls below the set point (considering hysteresis), the pilot valve closes, re-establishing pressure above the piston and shutting the main valve.

Advantages:

• Provides tight shutoff even close to the set pressure.
• Offers higher capacity and reduced leakage compared to direct spring-loaded valves.
• Features adjustable blow-down, which is the difference between the opening and closing pressure.
• More compact design suitable for high-pressure applications.

Disadvantages:

• Significantly more expensive than standard safety valves.