Check Valves
model C11, C21, C31
Check valves prevent flow reversal automatically, without external actuation. Valland manufactures two families: the swing check valve (model C11), with a hinged disc in a single-piece bolted-bonnet body, available with renewable or fixed seats, soft sealing or metal-to-metal, and a lockable disc option; and the dual plate check valve (model C21), with two spring-loaded half-discs in a compact lugged, wafer or double-flanged body with integral metal-to-metal seat.
The swing check design suits pipeline and pump/compressor discharge protection where full bore and low pressure drop matter, and can be hyperbaric tested for subsea installation. The dual plate design offers a much shorter face-to-face and lower weight, with faster closing dynamics that reduce water hammer.
Like the rest of the range, check valves are engineered per project: materials from carbon steel to super duplex, titanium and nickel alloys, NACE MR0175 compliance on request, fire testing per API 6FA/API 607 and fugitive emission testing per ISO 15848. A recent reference is the supply of 10.000 psi swing check valves to Harbour Energy for the Talbot & Affleck projects (UK).
| Applicable standards | Model C11: API 6D and API 6DSS Model C21: API 6D, Design according to ASME B16.34 or ASME VIII Div. 1 & 2 |
| Pressure Class Range | ANSI Class 150 lbs. to 4500 lbs. API6A Class 3000 PSI to 20000 PSI |
| Size Range | From 1/2" to 42" |
| Ends design | Flanged (RF/RTJ) - ASME B16.5, ASME B16.47 or MSS SP-44 Compact (Norsok Standard L-005) Butt-Weld (ASME B16.25) and/or Butt-Weld + Pipe Hubbed according to client Clamp Special client's requirements |
| Body Design | Model C11: Single piece Model C21: Lugged - Wafer - Double Flanged |
| Bonnet Design | Model C11: Bolted bonnet |
| Seat design | Model C11: Renewable or fixed, Soft sealing or Metal to Metal (c/w hardfacing) Model C21: Integral seat, Metal to Metal sealing |
| Stem Design | Model C21: Retainer or Retainerless |
| Valve operation | Model C11: Lockable disc option available |
| Available Materials | CS, LTCS, SS, Duplex SS, Super Duplex SS, 6Mo, Inconel, Incoloy, Hastelloy, Monel, Titanium NACE MR0175 according to client request. |
| Additional Features | Double Block and Bleed, Normal or Reverse acting, Graphite or V-Pack stem sealing arrangement |
| Testing and Certification | Testing: Hydrostatic and Pneumatic API 598 - API 6D Fire testing: API 6FA, API 607, BS 6755 part 2, ISO 10497 Fugitive Emission Test: ISO 15848 - 1 & 2 PED 2014/68/UE Mod.H Model C11: Hyperbaric Test for Subsea application |
