IMI TA STAD PN 25 Balancing Valve, NPT Threads

Manual balancing valve with digital presetting and measuring points

The IMI TA STAD (PN 25, NPT threads) is a manual balancing valve for heating, cooling and tap water systems. It is installed on branches and risers to set the design flow, measure the actual flow and differential pressure with a balancing instrument through two self-sealing measuring points, and shut the circuit off for maintenance. Hydronic balancing of this kind is required on chilled water and hot water networks in commercial buildings, hotels, hospitals and district cooling connections, because uneven flow causes cold or hot spots and wastes pump energy.

A handwheel with a digital read-out gives accurate, repeatable presetting, and the positive shut-off function allows isolation without losing the setting. The valve is made of AMETAL, the IMI dezincification resistant alloy, to extend life and reduce leakage risk.

Technical specifications

Values are from the IMI Pneumatex STAD, NPT threads leaflet (PN 25, DN 10-50, ed.3 01.2021). The instrument software names this PN 25 version STAD*.

Kv values and articles

Flow coefficient Kv in m3/h at a 1 bar pressure drop, by number of handwheel turns open (Kvs is the fully open value).

Size, thread, face-to-face length L, height H and article numbers from the data sheet:

Sizing, installation and ordering

Calculate Kv from the design flow and the allowed pressure drop, then read the preset from the leaflet diagram or HySelect software. Mount the valve with straight pipe runs of at least 5 DN upstream and 2 DN downstream (10 DN after a pump or tee) for the accuracy curve to apply, and set the valve by closing it, opening it the required turns and locking the preset with the Allen key. The valve can be installed against the arrow, but flow tolerance may be up to 5 % larger. Accessories include measuring point extensions, a handwheel, identification tags, Allen keys and EPP insulation for heating and cooling. For automatic flow control see the IMI TA-COMPACT-P pressure independent valve; more valves are under Control Valves.

How the IMI TA STAD works

The STAD is a valve with a variable orifice. The handwheel sets how far the valve is open, in turns, and a digital read-out shows the setting. Two measuring points sit on each side of the orifice. A balancing instrument connects to these points and reads the pressure drop, from which the flow is found. With the valve set to the design flow, each branch receives the water it needs. The positive shut-off function closes the valve without losing the preset.

Where the IMI TA STAD is used

• Chilled water and hot water networks
• Branches and risers in commercial buildings
• Hotels and hospitals
• District cooling connections
• Heating and tap water systems

Selection checklist for the STAD

• Size from DN15 to DN50
• Pressure class PN 25
• Temperature from -20 to 120 degrees C
• Internal NPT thread to ANSI/ASME B1.20.1
• Water or a water-glycol mixture of up to 57 percent
• Kv value needed for the design flow
• Draining version, if a drain is needed
• Balancing instrument for the measuring points

Installation, commissioning and maintenance notes

Fit the valve in the flow direction and allow straight pipe before it so the measurement is steady. Open it, connect the instrument to the measuring points and set the handwheel to the design flow. Lock the preset with the 3 mm Allen key and record the setting. Do not use the handwheel to throttle after balancing, and use the shut-off function for isolation.

Requesting a quotation for the IMI TA STAD

Please send the size, the thread type, the draining option and the quantity needed. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

STAD materials

The body, bonnet, plug and spindle are AMETAL, a dezincification resistant alloy, and the O-rings are EPDM.

STAD presetting

Four turns of the handwheel correspond to fully open, and the zero position is calibrated at the factory.

STAD flow coefficient

The fully open Kv value runs from 2.56 for DN15 to 32.3 for DN50 in cubic metres per hour at a 1 bar pressure drop.

STAD measuring points

The self-sealing measuring points are made of AMETAL with EPDM seals and have polyamide caps.

Balancing valve records for STAD

Keep the valve tag, the preset in turns and the measured flow with the commissioning file.

Choosing the right STAD size

Pick the size so the design flow gives a stable reading at several turns open, not at the lowest setting.

Documents and quotation

The attached leaflet gives the Kv table, setting diagram, accuracy data, dimensions and accessories. Send the size, whether a drain is needed, thread type and quantity for a quotation. Check that NPT threads suit the pipework, because other thread versions of the STAD range exist.

Related buying guide: Valves supplier in Oman for MEP projects: chilled water, plumbing and fire protection valves.