Certification and inspection documents

Service conditions

A check valve opens and closes automatically in response to fluid forces to restrict reverse flow. Its behavior depends on disc motion, velocity, differential pressure and installation orientation. Selection should consider flow changes and pump shutdown, balancing forward pressure loss against closing response.

Construction and description

For solids-bearing fluids, define particle size, hardness, concentration and settling tendency. Assess passage, seats and shaft seals for erosion and trapped material and review cleaning, drainage and wear-part replacement.

Define fluid composition and continuous and start-stop operating conditions, then assess body, internals and seals as a combination. Particles, deposits and cleaning affect sealing surfaces and mechanisms; plan maintenance for the actual service.