Pump ByPass Control
While many steel mills have implemented continuous bypass flow as a fail-safe method of ensuring that pumps don’t overheat or get damaged, this method wastes a tremendous amount of energy. Centrifugal pump bypass control helps steel producers improve quality and reduce the cost of production.
The integration of Hunt Valve’s pump bypass control valves (with built-in fail-safe features) delivers minimum flow for pump cooling only when needed—providing the capability to direct 100% of the flow to the descale header when required. This method allows steel producers to direct higher flows and pressures to improve the descale efficiency and product surface quality or shut down a pump by eliminating continuous bypass flow from multiple pumps, resulting in significant energy cost savings.
At Hunt Valve, our bypass valves are ideal for any high-pressure centrifugal pump system that requires minimum flow to provide cooling for the pumps when there is no system demand. With pump bypass control, you’ll experience enhanced efficiency, increased pressure for the application and potential energy savings.
Hunt Valve’s pump bypass control products provide fail-safe operation and pump protection in the following ways:
- Combined with our pressure breakdown orifices, our bypass valves eliminate the troublesome mechanical linkage and variable orifice design that is commonly used in minimum flow bypass applications.
- All Hunt Valve centrifugal pump bypass valves are designed to fail open in case of electrical power or pneumatic pressure loss to provide complete protection for your pump.
Hunt Valve offers the following versatile valve products for pump bypass control:
- Proportional Ceramic Pump Bypass (Minimum Flow) Valve
Hunt Valve’s proportional poppet valve for descaling pump bypass applications lasts three to five times longer than traditional poppet or automatic recirculation control (ARC) valves. The valve’s ceramic technology optimizes the component’s useful service life while the electromechanical actuation eliminates pilot shifting.
At steel mills, persistent water hammer from quick-shifting poppet-style descale pump bypass valves often leads to burst pipes, cracked welds and descale header damage. Hunt Valve’s proportional poppet valve eliminates water hammer in the system using a variable speed stroke profile—a technology that no other company is using for descale valves in the steel industry.
The stroke speed of the proportional ceramic pump bypass valve is programmed to travel at the closing or opening time/speed required to eliminate water hammer from the system. The rate of closure can be fine-turned via the integrated local control interface or programmable logic controller (PLC) to an optimum level for the hydraulic system. A typical stroke profile is rapid-closed and then transitioned to slow-close for the last 10–20% of the stroke or slow-opened until pressure is equalized between the valve and the pressure breakdown orifice.
Minimizing the effects of water hammer and system shock, the proportional pump bypass valve promotes safety, reduces annual operating costs and decreases unscheduled downtime in the plant. In addition, Hunt Valve is the only company using electromechanical linear actuator technology in its proportional poppet valve design to eliminate the shifting reliability issues commonly associated with media pilot valves.
- Pump Bypass (Minimum Flow) Valve
Hunt Valve’s Mega-Flo C Descale Valve is known around the world for its innovative design and quality engineering. This fast-acting, smooth-shifting product consistently provides high-pressure
water when needed. Formed from heat-treated and corrosion-resistant stainless steel, the valve’s radial-ported plunger is precision-machined and then plated with hard chrome.
With a radial-ported plunger design, the seal is pushed away from the plunger by the fluid pressure during shifting, offering a significantly longer seal life. In addition, the staggered flow slots provide gradual acceleration and deceleration of flow during plunger shifting to prevent damage to the piping system from velocity shock (water hammer).
The valve’s inherent wear-resistant design and stringent material specification help ensure a long service life for this critical component. In fact, the valve’s smooth-shift operation helps prolong the life of all components in the descaling system.