SEVERE HYDRAULIC TRANSIENTS CAPTURED ON VIDEO
(ANCONEWS VOL. 3, NO. 2)

WATER HAMMER SIMULATION

Under the sponsorship of the Electric Power Research Institute (EPRI), ANCO performed pressure wave and water hammer simulations on 2" and 6" diameter pipes and pipe restraints. Strut support failures, extreme elbow deformation, and failure of eroded/corroded pipe were produced in the course of testing. Response data were recorded using multichannel instrumentation and documented on video tape. EPRI has used this data in its piping and fitting dynamic reliability program, as support for new ASME code cases, and to produce a training video on water hammers to assist plant operating personnel to locate and understand water hammer damage.

TRANSIENT SIMULATOR SYSTEM

The ANCO hydraulic transient simulator is represented in the drawing at left. Energy to produce a pressure wave or moving water slug comes from pressurized nitrogen tanks acting through a rupture diaphragm. The surge can be vented to atmosphere, stopped at a dead end, or sent into a surge tank at pressure. The system can operate from 600 to 3,000 psi and has a drive gas volume of 10 cubic feet. Slug velocities up to 400 fps and peak pressures up to 8,000 psi have been achieved. Equipment such as valves can be placed in line to demonstrate design adequacy under hydrodynamic flow and shock forces.

CODES VALIDATED

ANCO has also performed laboratory simulation of BWR torus blowdown, and field measurements of actual water hammer events to validate computer codes (such as RELAP).