Resideo (Honeywell) TMV-00012 Thermostatic Expansion Valve – R404A/R502, Internal Equalizer, ±0…−50 °C

Resideo (Honeywell) TMV-00012 is an internally equalized thermostatic expansion valve operating with R404A / R507A / R402A / R407B / R502 refrigerants. It is specified for an evaporating range of ±0 … −50 °C — commercial refrigeration and low temperature applications.

Body with Interchangeable Orifice — No Need to Remove the Valve When the Capacity Changes

The biggest advantage of the TMV series in the field is that the orifice can be changed as a cartridge. When the evaporator capacity changes or the valve has been incorrectly selected, you do not need to remove the whole valve: you leave the capillary tube, the bulb and the flare connections in place and change only the internal VD orifice cartridge.

In practice, this reduces a valve replacement that takes hours to a 15-20 minute cartridge change; since you do not re-braze the line, there is no risk of leaks either.

Internal or External Equalizer?

An internal equalizer (TMV) takes the evaporator pressure from the valve's own body. It is the right choice for single-circuit evaporators with low pressure drop. If the evaporator has a distributor, or the circuit is long with a high pressure drop, the externally equalized TMVX should be used — in that case an internally equalized valve reads the superheat higher than it actually is and throttles the valve unnecessarily.

Technical Specifications (Official Honeywell SERIES TMV, EN0H-1900GE23)

• Model: Resideo (Honeywell) TMV-00012 | Series: TMV (internal equalizer)
• Compatible refrigerants: R404A · R507A · R402A · R407B · R502
• Thermostatic charge: adsorption (combi) charge — no MOP
• Evaporating range: ±0 °C … −50 °C
• Max. pressure (PS): 36 bar(a) | Test pressure (PF): 39.6 bar(a)
• Connection: inlet 5/8" UNF · outlet 3/4" UNF (flare)
• Capillary tube: 1.5 m | Bulb diameter: 12 mm
• Net weight: approximately 0.35 kg

🚨 Orifice Cartridge Not Included

The valve capacity is determined by the orifice, and the orifice is ordered separately. A valve without an orifice does not pass refrigerant. Select according to your evaporator capacity:

Capacities are at t₀ = +4 °C, t_c = +38 °C, with 1 K subcooling at the inlet.

• 🔧 Orifice selection: choose the value closest to and one step above the evaporator capacity. Too small an orifice cannot feed the evaporator (excessive superheat); too large an orifice makes the valve oscillate (hunting) and may let liquid through to the compressor.
• ⚠️ There is a large jump between 2.5 and 3.0 (4.1 → 6.5 kW with R404A). For systems that fall in between, choosing 2.5 and adjusting via the superheat usually gives a better result.
• Superheat adjustment: one full turn of the adjusting spindle changes it by about 0.55 bar. Clockwise = flow decreases, superheat increases.
• 🔧 Bulb placement: it is attached to the upper half of the horizontal suction line, is never placed after a liquid trap, and must always be insulated. Do not crush the bulb when clamping it.
• ⚠️ Brazing warning: the valve body must not exceed 100 °C during brazing. When tightening the flare nuts, hold the valve by the wrench flats on the body.
• Advantage of the adsorption charge: this type of charge is not affected by the temperature of the capillary tube and valve head — it operates only according to the bulb temperature. It remains stable even during icing and hot gas defrost.