IMI TA-Modulator Pressure Independent Control Valve DN 10-200

Overview

The IMI TA-Modulator is the IMI TA pressure independent balancing and control valve for modulating control. Where small on/off terminal valves stop, it covers the full span of an HVAC water system: threaded AMETAL bodies from DN 10 to DN 50 for fan coils, chilled beams and small air handling coils, and flanged ductile iron bodies from DN 65 to DN 200 for air handling units, heat exchangers and plant room circuits. Its uniquely shaped EQM characteristic gives precise temperature control, and the built-in differential pressure controller gives high control authority and automatic limitation of the design flow. Across the range, the maximum flow can be set from 17 l/h up to 329,000 l/h on the DN 200 high flow version.

Seven Star LLC supplies the IMI TA-Modulator together with TA-Slider actuators to consultants, MEP contractors and facility managers in Oman and the GCC. Our team in Muscat helps choose between normal and high flow versions, checks the available differential pressure, and prepares submittal documents from the manufacturer datasheet.

Operating Principle

Each valve has a control plug, positioned by a linear, proportional or 3-point actuator, and a differential pressure insert that keeps the pressure drop across the control part constant. Because that pressure drop stays fixed, the valve authority stays high and the flow at each stroke position does not drift with pump speed or with loads elsewhere in the system. When the actuator is fully open, the flow is limited to the value set on the presetting scale, so the IMI TA-Modulator also acts as an automatic balancing valve and protects the network against overflow.

The EQM characteristic is the key difference. IMI states that it provides an up to 6 times larger operating stroke than linear valves, which gives the controller more resolution at the low flows where coils spend most of their time. The DN 50 to DN 200 high flow (HF) versions use a linear characteristic for duties where very large flow matters more than modulation shape. Measuring points let IMI TA balancing instruments read flow and available differential pressure, so the commissioning engineer can verify each IMI TA-Modulator and reduce the pump head to the lowest value that still satisfies the index circuit.

Engineering Design of the IMI TA-Modulator

DN 10 to 32 sizes have an AMETAL body and insert, a brass CW724R plug, stainless steel spindle and springs, PPS and AMETAL differential pressure insert and EPDM membrane, with a pressure class of PN 16 and a working temperature of minus 20 to 120 degrees C (minus 10 to 90 degrees C for DN 10 to 25 with PPS insert). DN 40 and 50 are PN 25 with AMETAL bodies and a PTFE-faced plug. The flanged DN 65 to 200 IMI TA-Modulator uses ductile iron EN-GJS-400-15 for body and insert, a stainless steel and EPDM plug, aluminium bronze seat and reinforced EPDM membrane, is available in PN 16 or PN 25, and has flanges to EN 1092-2 type 21 with face-to-face length to EN 558 series 1.

Lift ranges from 4 mm on DN 10 to 20 up to 32.5 mm on DN 200. Rangeability is above 50 on DN 10 and DN 15 LF, above 75 on DN 15 to 32, above 125 on DN 40 to 80 and on DN 200, and above 150 on DN 100 to 150. Leakage with the plug closed is 0.01 percent or less of maximum qmax with correct flow direction. Actuator connections are M30x1.5 for DN 10 to 50 and 2xM8 push/pull for DN 65 to 200, matched to TA-Slider 160, 500, 750 and 1600 actuators, which are also available with a fail-safe function.

Key Features

The IMI TA-Modulator offers the following engineering advantages:

• One valve family from DN 10 to DN 200, threaded and flanged, with normal and high flow versions.
• Shaped EQM characteristic for precise modulating control, with up to 6 times larger operating stroke than linear valves.
• Built-in differential pressure controller for high authority and automatic limitation of design flow.
• Maximum differential pressure up to 600 kPa on DN 10 to 50 and 800 kPa on DN 65 to 200.
• Flow settable from 17 l/h on DN 10 up to 329,000 l/h on DN 200 HF.
• Measuring points for flow and differential pressure, supporting diagnostics and pump optimisation.
• Corrosion-resistant AMETAL or electrophoretically painted ductile iron bodies, with glycol up to 57 percent tested.
• Matching TA-Slider actuators with proportional, 3-point and fail-safe options.

Industrial Applications

In a typical Gulf commercial building, the same chilled water network feeds hundreds of fan coils at the room level and a smaller number of large air handling units at the plant level. Using the IMI TA-Modulator at both levels gives one balancing and control philosophy throughout, with the same commissioning instruments and the same setting procedure. The small threaded sizes suit fan coils and chilled beams in hotels, offices and apartments, while the flanged sizes handle AHU coils, fresh air units and plate heat exchangers in hospitals, airports, malls and district cooling energy transfer stations in Muscat, Duqm and Salalah.

Because flows stay at design values regardless of pump speed, the IMI TA-Modulator helps keep chiller delta-T high and supports variable primary or variable secondary pumping strategies that reduce energy use. Seven Star LLC supplies the IMI TA-Modulator with TA-Slider actuators and accessories, and supports contractors across Oman, the Sohar and Salalah free zones and the GCC with sizing and documentation.

Technical Specifications

Main IMI TA-Modulator data from the IMI datasheet:

How to Order

For pricing and availability of the IMI TA-Modulator, send Seven Star LLC a valve schedule or a formal RFQ. Our instrumentation division in Muscat will confirm sizes, flow versions and actuators, share the manufacturer datasheet available for download on this page, and coordinate supply with engineering support for Oman and the GCC. See also the Belimo EPIV flanged electronic PICV, the Grundfos NB end-suction pump and the pFlow GFCL ultrasonic flowmeter for HVAC.