BELIMO Automation - Pressure Independent Characterised Valve Overview

Pressure Independent Characterised Valve Overview - Concept - Advantages

The Concept

The Pressure Independent Characterised Control Valve (PICCV) consists of a differential pressure regulator in series with a control valve.

The key to the PICCV is the regulator assembly. This regulator controls the amount of flow that passes through the valve by the use of a diaphragm that moves according to the change in pressure above and below it.

The pressure regulator absorbs pressure variations so the differential pressure is constant over the control valve section thereby giving the same flow, regardless of pressure variations in the system.

This leads to optimum heat transfer, minimum flow, and high delta T. Achieving design delta T or greater minimises energy consumption, and allows the full installed capacity of the plant to be delivered.

Operational Theory

Performance

The pressure within the pipework decreases with increasing distance from the main pump. In order to equalise these differences, additional commissioning sets are installed in addition to the control valves.

These commissioning sets can be dispensed with in the future, since the new pressure-independent control valve R2…P from Belimo eliminates the need for a hydraulic compensation. The integrated pressure-reducing valve automatically closes when the differential pressure increases and ensures a constant pressure over the control valve. This creates the prerequisite for maintaining a constant flow rate (± 5% at a differential pressure of 30...350 kPa).

• Controls temperature exactly – especially at light loads
• Lowers system energy expenses through efficient heat transfer
• Increases actuator life expectancy – fewer movements needed to maintain set point
• Set maximum flow with Multi-Function Technology actuators for warm-up, cool-down or any flow in litres per second you choose
• Energy can be measured & displayed because PICCV provides a specific flow for each degree of opening
• Achieve controllability in any situation!

Advantages

Hydraulic balancing is no longer necessary. Equipping a building becomes simpler and only one valve per consumer is needed. Since no more balancing valves are needed and the hydraulic balancing is eliminated, it is possible to save costs while - at the same time - increasing convenience.

• Easy valve sizing with no kv calculations
• Easy commissioning
• Optimised valve authority
• Reduced installation & pumping costs
• Increased equipment efficiency
• Predictable flow for each degree of opening

The Corresponding Drives

Optimum functionality of the Belimo pressure-independent characterised control valve is ensured by the corresponding motorisation. Depending on the application, the PICCV are supplied with different rotary actuators. Depending on the type, they can be controlled by a modulating or 3-point control system.

Cost

• Replace balancing valve, control valve & balancing labour with a single PICCV – at less cost
• Replace installed two-way control valves with no system changes, & receive much improved performance & stable control
• Reduce total installation cost
• Replace automatic flow-limiting valves
• No cartridge cleaning or maintenance required
• Eliminate design & analysis cost of valve sizing
• Simply choose the smallest PICCV to satisfy the flow requirement
• No need to consider piping geometry factors into sizing

Product Range

• 15mm to 50mm, ISO 7/1 Internal Thread
• 0.09 l/s to 5.05 l/s flow rate
• Non-spring return and spring return actuator options
• On-off, 3-point and modulating actuators available
• MFT functionality
• Set l/s required
• Complete control resolution over opening of valve
• Opening and closing points set on-site or by Belimo