Disc check valve - CHECKO D | ARI

ARI-CHECKO®-D – Spring-Loaded Disc Check Valve

The ARI-CHECKO®-D is a wafer/clamping type spring-loaded disc check valve designed for installation between flanges. Flow lifts the disc; the spring returns it to the closed position when differential pressure drops below the opening pressure, preventing reverse flow without the need for an actuator.

Technical Specifications

• Type: ARI-CHECKO®-D 001
• Pressure rating: PN40
• Body material: 1.4408 (stainless steel)
• Disc/plate: 1.4571
• Spring: 1.4310
• Sizes: DN15–DN100; DN125–DN350 on request
• Opening pressure: 0.02 barg
• Face-to-face: EN 558, Series 49
• Kvs: 4.4 to 122 m³/h for DN15–DN100

Sealing Options

Standard version features metal-to-metal sealing, leakage class BN2/BO3 per DIN 3230-3 and leakage rate D per DIN EN 12266-1. Optional soft seats available: EPDM up to 120°C, NBR up to 80°C, FPM/Viton up to 150°C (leakage class A, DIN EN 12266-1). FPM version is not intended for hot water service.

Applications

Suitable for water, condensate, steam, thermal fluids, and compatible industrial liquids or gases, provided pressure-temperature ratings and chemical compatibility with 1.4408, 1.4571, and seat material are verified.

Installation Guidelines

Ensure correct flow direction, clean piping, and centered gaskets. For stable operation, use straight pipe runs of at least 2×DN upstream and 6×DN downstream. In lines downstream of pumps or with pressure pulsations, assess hydraulic behavior—low flow or oversizing may cause chatter and wear.

FAQ

Does it have an actuator? No, it operates via differential pressure and spring force.
When is a soft seat selected? For reduced seat leakage, subject to temperature and media compatibility.
Where is wafer construction used? In compact piping systems where short installation length is critical.