Needle valves are the suitable valve to use whenever pressure heads or flow rates need to be safely and reliably reduced and controlled. They are used for two main tasks :
• By restricting the cross-section, a change in flow rate, flow velocity and pressure is forced, which results to higher stress in the valve. The valve must therefore be designed so that potential cavitation cannot cause any damage whatsoever.
• To be able to control the pressure and flow precisely and finely, the control valve’s control characteristics must be as linear as possible over the whole opening range.
Thanks to their well thought out design, ERHARD needle valves fulfil these requirements to the greatest possible degree and are therefore the ideal valve for numerous control tasks.
Because even if butterfly valves and gate valves are used for such tasks in individual cases in practice, due to their design as an optimum shut-off device for “OPEN/CLOSED” operation, but they are not suitable for continuous use as a control valve.
New challenges ...
The production and operation of control valves requires sophisticated knowhow, to enable the differentiated requirements to be fulfilled :
• International standards, approvals and test regulations set the highest quality requirements.
• The increased cost of energy requires optimum flow performance with minimum pressure losses to ensure economic operation.
• And last but not least, long life valves and low maintenance costs ensure that the personnel costs necessary for operation are minimised.
After all, nowadays, all the costs incurred over the whole life of the valve (life cycle costs) play a decisive role in the choice of product.
... and the solutions from ERHARD
The wide range of ERHARD needle valves fills these requirements in a particular way.
They are especially suitable for drinking water, raw water and air. Their typical applications include use as:
• Pump start-up and control valve
• Reservoir inlet
• Control device in the bottom outlet valve of dams (with or without venting)
• Control device in the inlet and bypass of turbines
• Safety device in the bypass outlet of turbines for quick opening
• Control and simultaneous safety device in pipe systems (e. g. pump pressure pipes)
Innovative and customer-focused product development, state of the art engineering, production and assembly technology and continuous quality assurance throughout take place at ERHARD, concentrated in one location for top quality “Made in Germany” before, during and after installation.