Brand: Spirax Sarco

Spirax Sarco ILVA Self-Acting Variable Area Flowmeter

Name: Spirax Sarco ILVA Variable Area Flowmeter – Datasheet
Brand: Spirax Sarco

Description

Overview

The Spirax Sarco ILVA is a self-acting, spring-loaded variable area flowmeter built on the proven Gilflo measurement principle, designed to deliver accurate, repeatable flow measurement of steam, condensate, liquids, and gases without external power. Unlike orifice-plate or fixed-area devices that lose accuracy at low flow, the ILVA’s variable annular measurement area automatically compensates as flowrate changes, giving it an unrivalled 100:1 turndown ratio and typical accuracy of ±1% of reading across the full measurement range. This makes the Spirax Sarco ILVA a first-choice flowmeter wherever plant loads swing widely between minimum and peak demand, a common condition in steam and condensate networks serving process heating, utilities, and district energy systems.

Backed by manufacturer datasheet documentation, Seven Star LLC proudly supplies the ILVA flowmeter to utilities, process, and energy-management teams across Oman and the wider GCC. Facility engineers in Muscat, Sohar, and Salalah can source Spirax Sarco ILVA units through Seven Star LLC with manufacturer documentation and local technical support for this critical metering equipment.

Measurement Principle

The Spirax Sarco ILVA operates on the spring-loaded variable area principle. As process fluid flows through the meter body, it acts on a spring-loaded piston, deflecting it against a calibrated spring so that the annular flow area increases in direct proportion to the flowrate. This deflection produces a differential pressure signal across the piston that is directly and predictably related to flow, without needing a separate orifice plate, venturi, or external power source to generate the measurement signal. Because the flow area itself changes with load, the ILVA maintains a strong, stable differential pressure signal at both very low and very high flows, which is the fundamental reason it achieves 100:1 turndown where fixed-geometry meters typically manage only 3:1 or 4:1.

The differential pressure signal generated by the ILVA can be read locally or transmitted via a mass flow transmitter such as the Spirax Sarco MVT10 for integration into a plant control system, enabling both saturated and superheated steam mass flow calculation, totalization, and remote monitoring. Because the meter has no orifice restriction to foul or wear unevenly, and no moving electronic components in the primary measurement path, it delivers consistent accuracy over long service intervals with minimal maintenance, and its self-acting mechanical design means it continues to provide a usable reading even in the event of a loss of instrument power to any connected transmitter.

Engineering Design of the Spirax Sarco ILVA

The Spirax Sarco ILVA is available in flanged, in-line configurations from DN100 up to DN300, constructed from robust stainless steel and carbon steel body materials rated for operating pressures up to 1450 psi and temperatures from -29°C to 400°C (-20°F to 752°F), covering saturated and superheated steam duties as well as general liquid and gas metering. The piston and spring assembly is fully removable for inspection or recalibration without disturbing the pipeline flanges, and the meter body accepts a range of local indicators, differential pressure transmitters, and mass flow computers depending on whether the application requires a simple visual rate indication or a fully integrated 4-20 mA / digital output for the plant SCADA system.

Installation follows standard flanged in-line practice with defined upstream and downstream straight-pipe requirements, and the ILVA20 variant is commonly paired with the Spirax Sarco MVT10 differential pressure and mass flow transmitter for saturated and superheated steam service, giving a fully engineered flow measurement package rather than a bare mechanical sensor. The compact stem design available on the larger DN250 and DN300 sizes reduces overall installed footprint in constrained plant rooms, a frequent constraint in retrofit projects across older GCC process facilities.

Key Features

The Spirax Sarco ILVA combines mechanical simplicity with wide-range accuracy, and the following Spirax Sarco ILVA features explain why it remains a preferred flowmeter for steam and process utilities across Oman and the GCC:

Self-acting, spring-loaded variable area design requires no external power to generate a flow signal.
Unrivalled 100:1 turndown ratio, far exceeding the typical 3:1 to 4:1 range of fixed-geometry meters.
Typical accuracy of ±1% of reading maintained across the full flow range.
Suitable for steam, liquids, and gases, including saturated and superheated steam service.
Available in flanged in-line sizes from DN100 to DN300 for a wide range of pipeline diameters.
Operating range from -29°C to 400°C and pressures up to 1450 psi covers demanding process duties.
Compatible with the Spirax Sarco MVT10 mass flow transmitter for full digital integration.
Removable piston and spring assembly simplifies inspection and recalibration without pipeline disruption.

Industrial Applications

The Spirax Sarco ILVA is widely deployed on steam and condensate distribution mains where load varies significantly between shifts or seasons, including central utility plants, process heating headers, and boiler house steam metering for energy accounting and cost allocation between departments or tenants. District cooling plants, RO desalination pre-treatment steam systems, and hospitality and hospital complexes across the region use the ILVA to track steam consumption accurately at both base-load and peak-demand conditions, supporting energy audits and utility cost recovery programs.

Working closely with plant engineers in the region, Seven Star LLC distributes the ILVA flowmeter to utility, process, and facilities management teams throughout the Sultanate of Oman and the GCC, including the Sohar and Salalah industrial and free zones where large steam-consuming industries continue to require accurate, wide-turndown flow measurement for both operational and regulatory reporting purposes. Engineers in Muscat and across the region rely on Seven Star LLC for genuine ILVA units, sizing support, and integration guidance with mass flow transmitters and plant control systems.

Technical Specifications

The table below summarizes the key technical specifications of the Spirax Sarco ILVA self-acting variable area flowmeter.

Parameter	Specification
Model	Spirax Sarco ILVA (Gilflo ILVA)
Measurement Principle	Self-acting, spring-loaded variable area
Turndown Ratio	100:1
Accuracy	±1% of reading
Available Sizes	DN100, DN150, DN200, DN250, DN300
End Connections	In-line flanged
Operating Temperature Range	-29°C to 400°C (-20°F to 752°F)
Maximum Operating Pressure	Up to 1450 psi (1021 m H²O)
Process Media	Steam (saturated and superheated), liquids, gases
Compatible Transmitter	Spirax Sarco MVT10 mass flow transmitter
Body Materials	Stainless steel / carbon steel construction

Request a Quote for Spirax Sarco ILVA Self-Acting Variable Area Flowmeter

Utility and process engineering teams evaluating wide-turndown steam and flow metering are invited to submit a formal RFQ for the Spirax Sarco ILVA through Seven Star LLC. With fast quotation turnaround and technical support, Seven Star LLC supplies on request, provides full technical datasheets on request, and connects buyers directly with the instrumentation division for sizing, MVT10 transmitter pairing, and installation guidance.

Reviews

There are no reviews yet.

How would you rate this product?

About brand

Spirax Sarco is the British steam engineering company known for steam traps, pressure reducing valves, stop valves, separators and steam flowmeters. Its roots go back to 1888, when Herman Sanders founded a London business importing thermostatic steam traps under the Sarco name. The Spirax brand followed in 1932, the company moved to Cheltenham in 1937, and it was listed in 1959. The group now trades as Spirax Group and is still headquartered in Cheltenham.

Seven Star LLC is an independent supplier in Muscat. We list Spirax Sarco steam traps, valves, clean steam equipment and flowmeters, and supply them to boiler houses, hospitals, food plants and process plants in Oman and the GCC.

Spirax Sarco at a glance

Origins	1888, London: Sanders, Rehders & Co. ("Sarco") imports thermostatic steam traps
Milestones	Spirax brand in 1932; move to Cheltenham in 1937; listed as Spirax-Sarco Engineering in 1959; now Spirax Group plc
Headquarters	Cheltenham, United Kingdom
Product families	Steam traps, pressure reducing and control valves, stop and check valves, separators and filters, steam flowmeters, clean steam generators and sanitary valves

Spirax Sarco products we list

Family	Models	Typical use
Steam traps	TD42, TD120M, FTS14 ball float, BT6-B, BPC32YF, BPS32, BTM7, PC4000 connector, STS17.2 station, AVM7 air vent	Draining condensate and venting air from mains, tracing and process equipment
Pressure reducing and surplussing valves	DP27, BRV71/73, SRV2S, SRV66, SDP143	Reducing boiler pressure to the pressure the user needs, and protecting the boiler from overload
Stop, check and ball valves	BSA/BSAT, BSA3HP, BSA3BD, A3S, DBB3, DCV1, M10S	Leak-free isolation on steam with bellows-sealed stems, and backflow prevention
Clean steam and sanitary	CSG-HS generator, CS10 separator, CSF16 filter, STERI-TROL, SVL488 safety valve, M70i	Hospitals, sterilisers, pharmaceutical and food production
Steam flowmeters	ILVA, TVA, TFA	Measuring steam use per boiler, building or process

Good steam systems remove condensate and air as soon as they form, because water in a steam line causes water hammer and wet steam carries less usable heat. Thermodynamic traps like the TD42 suit steam mains and tracing. Ball float traps like the FTS14 discharge continuously and suit heat exchangers. Balanced pressure traps vent air quickly at start-up. A trapping station such as the STS17.2 puts the isolation valves, strainer and trap on one connector, so the trap can be changed in minutes.

Where Spirax Sarco products are used

In Oman and the GCC, Spirax Sarco equipment is used in boiler houses of refineries and petrochemical plants, power and desalination stations, hospitals, hotels and laundries, and food, beverage, dairy and pharmaceutical plants.

Ordering Spirax Sarco products: what we need

Send the model, size (DN), end connection, body material and pressure rating. For steam traps, add the operating pressure and condensate load. For pressure reducing valves, add the inlet and outlet pressure and the steam flow in kg/h.

Facts checked against Spirax Group company history, October 2026.

Browse Spirax Sarco products by category: Clean Steam, Globe Valve, Flowmeters.

FAQ

Questions about the Spirax Sarco ILVA Self-Acting Variable Area

Answers from our engineering team on installation, compatibility and integration.

01What makes the Spirax Sarco ILVA suitable for widely varying flow loads?

The ILVA uses a self-acting, spring-loaded variable area principle that automatically adjusts its measurement area as flow changes, giving it an unrivalled 100:1 turndown ratio compared to the 3:1 to 4:1 range typical of fixed-geometry meters.

02How accurate is the Spirax Sarco ILVA flowmeter?

The ILVA typically delivers accuracy of plus or minus 1 percent of reading maintained across its full flow range, including at the low-flow conditions where many other flowmeter technologies lose accuracy.

03What pipe sizes and process media is the ILVA compatible with?

The ILVA is available in flanged in-line sizes from DN100 up to DN300 and is suitable for steam, including saturated and superheated steam, as well as liquids and gases, with operating pressures up to 1450 psi.

04Can the ILVA be integrated with a plant control system or SCADA?

Yes, the ILVA can be paired with the Spirax Sarco MVT10 differential pressure and mass flow transmitter to provide a 4-20 mA or digital output for saturated and superheated steam mass flow calculation and remote monitoring.

05Is Seven Star LLC an experienced supply partner for Spirax Sarco products?

Yes, Seven Star LLC is an experienced supplier of Spirax Sarco in Oman and the GCC, supplying genuine products with manufacturer documentation and local technical support.