API 6A High-Pressure Gate Valve Throttling Resistance

Internal hydrodynamic throttling and pressure drop across a partially closed (~35% open) API 6A gate valve under high-pressure water flow, verified against API standard resistance coefficients and Idelchik handbook.

Tolerance:

5%

Problem statement

Geometry

High-pressure gate valve flow path (bore D = 80 mm, length 420 mm, bonnet cavity 80 × 64 × 95 mm) with throttling gate slab inserted to Z = -12 mm leaving a crescent opening.

Material

Water at 20 °C (rho = 998.2 kg/m³, mu = 1.002e-3 Pa·s).

Boundary conditions

Inlet velocity U = 3.5 m/s along +X (intensity 5%), outlet gauge pressure 0 Pa, no-slip viscous walls on pipe bore, cavity walls, and gate slab.

Measured quantity

Static pressure drop Delta_p across the throttling gate (target 1.700 MPa from handbook resistance coefficient zeta ≈ 278) and flow continuity between inlet and outlet.

WebCAE Terminal

units mm
import path="cfd_api6a_gate_valve.step" format=step
mesh tet size=8
cfd fluid water
cfd set mode=steady speed=3.5 turbulence=sst iterations=220 tol=1e-4 threads=8 intensity=5 multigrid=1 cfl=8
cfd inlet surface number 8 speed=3.5 intensity=0.05
cfd outlet surface number 7 pressure=0
cfd wall surface number 1 monitor=on
cfd wall surface number 2 monitor=on
cfd wall surface number 3 monitor=on
cfd wall surface number 4 monitor=on
cfd wall surface number 5 monitor=on
cfd wall surface number 6 monitor=on
cfd wall surface number 9 monitor=on
cfd wall surface number 10 monitor=on
cfd wall surface number 11 monitor=on
cfd wall surface number 12 monitor=on
cfd wall surface number 13 monitor=on
cfd wall surface number 14 monitor=on
solve cfd

Results comparison

Updated: 2026-10-19 · WebCAE solver