Viat Instrument

Viat Instrument

Viat, is a family founded, owned, and run organization that manufactures instruments and accessories for transformers for the last 50 years. Today, we have manufacturing facilities in two Indian cities and dozens of global distributors and warehouses with whom we can ship to any country in the world. Viat supplies to over 500 transformer OEMs in 70 countries and is widely approved by utilities and OEMs globally.

General Description of Viat Instrument

The Viat founders started transformer instrument manufacturing with a company called ‘Atvus’ in 1970, making Buchholz relays in the living room of an apartment. The operations of Atvus were eventually merged into Viat Instruments, which was formed in 1995.

Today, Viat has over 50,000 square feet of covered area in our manufacturing facilities, which are in two separate cities providing redundancy and organisational depth. We offer the widest range of models and are among the largest global manufacturers for several of the product categories we supply.

We have been one of the fastest growing suppliers of instruments of components in the world of transformers.

  • Instruments in operation in over 10,000,000 transformers in 70 countries.
  • Presence in every continent. Customer list includes over 500 transformer manufacturers including most leading brands worldwide.
  • 50 years of experience in the transformer industry
  • Export house status is granted by the Govt. of India.
  • Constant R&D helps us improve products. Launching better models regularly helps us improve transformer protection, as needed by the industry.
  • We customize products to meet individual requirements.
  • Product design and quality standards are continuously upgraded
  • A very responsive team for both sales and after sales services.

Line of Business Viat Instrument

Magnetic Oil Level Gauge

Magnetic Oil Level Gauge
Magnetic Oil Level Gauge

Continuous oil level monitoring specially developed for use in transformers and compatible with all kinds of oil used in them. High contrast dial with a bright coloured indicator to show oil levels at different temperatures as well as minimum and maximum oil levels. Switches are factory calibrated and various setting options including high, low and very low are possible.

Liquid Level Indicators for Distribution Transformers

Liquid Level Indicators for distribution transformers
Liquid Level Indicators for distribution transformers

Our liquid level indicators provide visual indication to the level of oil inside a tank. These instruments are compact, flange mounted and have a radial moving float. They have large dials with high contrast marking for ease of use.

Pressure Relief Valves And Devices

Large Pressure relief devices with without contacts
Large Pressure relief devices with without contacts

These Pressure Relief Devices are recommended to be used on all sizes of transformers ranging from distribution transformers to large power transformers. For very large power transformers, it is usual to use multiple devices. There is no general formula or standard to link the size of the device to the size of the tank. This parameter is decided by the transformer designer or as agreed upon with the end user. As a general practice, one device can be used for every 38,000 litres (10,000 US gallons) of cooling liquid.

Gas Actuated (Buchholz) relay

Buchholz relays with magnetic reed switch
Buchholz relays with magnetic reed switch

The magnetic switches consist of two thin reed contact blades hermetically sealed inside a glass capsule n an atmosphere of dry inert gas. the switches are operated by a permanent magnet. the operating principle of the magnetic switches is very simple: when a magnet approaches the switch, the reeds close the circuit and when the magnets moves away from the switch, the contact gets open.

Radiator Valves

Radiator valves, Bolt-On, Cast Iron
Radiator valves, Bolt-On, Cast Iron

The valve mainly consists of machined flange, flap, spindle and locking cap. The flap is machined to fit the bore. The spindle is riveted to the flap and can be rotated in either direction to operate the valve. The cap on top of spindle locks the valve in the open or closed position, which is indicated on the exposed plate marked open/shut.

Read More : FTI Flow Technology

Rapid Pressure Rise Relay

Rapid pressure rise relays are designed to respond to rates of pressure change above predetermined safe limits set by the transformer manufacturer.

Rapid Pressure Rise Relay
Rapid Pressure Rise Relay

The purpose of this device is to detect a fault in a transformer quickly, while the pressure is still increasing and before the destructive effects of overpressure triggers the pressure relief device. The RPRR switches a set of contacts to indicate that it has detected a fault.

The RPRR is designed not to respond to normal pressure variations caused by temperature variation, mechanical shock and vibration or pump surges.

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