Pressure Relief & Surge Anticipator Valve

  • Protects Against Water Hammer Surges
  • Opens on Initial Low Pressure Wave
  • Closes Slowly to Prevent Subsequent Surges
  • Adjustable Over a Wide Range of Settings

The Cla-Val Model 52-03 Surge Anticipator Valve is indispensable for protecting pumps, pumping equipment and all applicable pipelines from dangerous pressure surges caused by rapid changes of flow velocity within a pipeline.

When pumping systems are started and stopped gradually, harmful surges do not occur. Should a power failure take place, however the abrupt stopping of the pump can cause dangerous surges in the system which could result in severe equipment damage.

Power failure to a pump will usually result in a down surge in pressure, followed by an up surge in pressure.

The surge control valve opens on the initial low pressure wave, diverting the returning high pressure wave from the system.*In effect, the valve has anticipated the returning high pressure wave and is open to dissipate the damage causing surge. The valve will then close slowly without generating any further pressure surges.

* An adjustable hydraulic flow control limits the valve opening for a controlled initial surge relief.

Schematic Diagram

  1. 100-01 Hytrol Main Valve
  2. X102F Flow Limiter
  3. X101 Valve Position Indicator *
  4. CK2 Isolation Valve
  5. 100-01 Hytrol (Reverse Flow)
  6. CRL-60 Pressure Relief Control
  7. CRA Pressure Reducing Control
  8. X58B Restriction Tube Assembly
  9. CSC Swing Check Valve
  10. X42N-3 Strainer Needle Valve
  11. Bell Reducer
  12. Pressure Gage
  13. CK2 Isolation Valve
  14. CK2 Isolation Valve

* Note: X101 or X105L Accessories not available in 4″ and smaller sizes.

Typical Application

The Model 52-03 discharges to atmosphere from a tee in
the pump discharge header. The valve anticipates surges
caused by power failure as well as acting as a standard
overpressure relief valve.


  • The remote pressure sensing line should be 3⁄4″ minimum I.D. installed from the valve to the pipeline to avoid air pockets.
  • We recommend protecting valve and tubing from
    freezing temperatures.

Model 52-03 (Uses 100-01 Hytrol Main Valve)Pressure Ratings (Recommended Maximum Pressure - psi)


Model 52-03 Dimensions (In Inches)

Model 52-03 Metric Dimensions (Uses 100-01 Hytrol Main Valve)

Model 100-01 FullPort Hytrol Main Valve

Surge View Analysis Overview
“SurgeView” is available as a service to specifying engineers to aid in the selection the best Cla-Val products to prevent and relieve surges.

The software plots the results of the transient in real time and “animates” the transient waves over the period of the transient event.

Learn more at:

Model 52-03 Dimensions

Sizing Information: Because of the many variable conditions that generally exist in any given system, proper sizing is important. Incorrect valve sizing will nullify the ability of the Surge Anticipator Valve. For valve sizing assistance, contact Cla-Val with the following specific pump and system information: number and type of pumps; shutoff head; flow rate; discharge static head and pumping head; pipe size; length; thickness and material.

CRL-60 Pilot Control
Direct-acting, spring loaded, diaphragm type relief pilot capable of opening and closing within very close pressure limits.

CRA Pilot Control
Automatically reduces a higher inlet pressure to a lower outlet pressure. Direct acting, spring loaded, diaphragm type – hydraulic or pneumatic operation.

Adjustment Ranges

High Pressure Pilot (CRL-60)
0 to 75 psi
20 to 200 psi *
100 to 300 psi
250 to 600 psi

Low Pressure Pilot (CRA)
2 to 30 psi
15 to 75 psi
30 to 300 psi *

*Supplied unless otherwise specified
Other ranges available, please consult factory

Temperature Range
Water: to 180°F

Standard Pilot System Materials
Pilot Control: Low Lead Bronze
Trim: Stainless Steel 303
Rubber: Buna-N® Synthetic Rubber

Optional Pilot System Materials
Pilot systems are available with optional
Aluminum, Stainless Steel or Monel materials.

Valve Options

X141 Pressure

Valve Position

X101AR Valve
Position Indicator
with Air Release

X144 e-FlowMeter

Steel Pilot