Hopkinson’s, previously known as J. Hopkinson and Company, is a manufacture of valves and boiler safety equipment currently part of Trillium Flow Technologies.

The company was founded in 1843 by Joseph Hopkinson in the upstairs room of a cottage workshop in Huddersfield. At the time the area was still suffering from the effects of the previous years General Strike, also know as the Plug Riots. Initially the new company focused on producing equipment for boilers that was more advanced than the then crude items in use that had caused many serious accidents. Due to the use of Haystack and Wagon boilers, with their relatively crude control and safety control equipment, the company soon relaised a need for this improved equipment.

By 1845 the company had expanded and moved to a new site in two converted cottage in Lockwood. From here it produced the Compound Safety Valve, which was used to prevent boiler explosions and was later developed into the Duad Safety Valve. In 1851 the company exhibited its products at the Great Exhibition, where it received a medal and certificate from Prince Albert. The following year it would offer a prize of £200 to anyone who could cause a boiler to explode when fitted with one of their compound safety valves. Confidence in their products was further illustrated by the Steam Users Association, who offered a 10% discount on their premiums *if the boiler was fitted with Hopkinson equipment. This again caused to company to expand and it moved to a new premise on Leeds Road, Huddersfield.

In 1854 the company introduced the Hopkinson’s type water gauge along with a mercurial type steam pressure gauge and an ‘Economical Self-Cleaning Boiler’ with a working pressure 100 lb/in2, when at the time most boilers operated at around 40 lb/in2. By 1857 the company had produced a boiler capable of being used at 200 or 250 lb/in2.

At around this time the company introduced the Hopkinson’s Steam Engine Indicator, an improvement on James Watt’s invention, which was used to improve the efficiency of steam engines by resetting the valve timings. This was promoted by offering to do this work for free if it resulted in less than a 10% improvement in horsepower, otherwise it would be charged at 7/6 per horse and 25% of the cost of the coal saved over 2 years. Following this Hopkinson would write a book entitled ‘Hopkinson on the Indicator’ which contained a great deal of information on the management of steam engines and boilers. This was recognised as making an important contribution to the knowledge on the subject, although it attracted a critical review from the Engineer magazine, who did not print his reply which resulted in his threatening a horse whipping.

In 1867 John Addy and Joseph, the founder’s sons, joined the company and it changed its name to J. Hopkinson & Co. In 1870 it would introduce the Hopkinson’s Deadweight Safety Valve, which contained a lockable cover to prevent interference, and the following year moved to a new site on Viaduct Street.

In 1881 the company patented the Hopkinson’s Parallel Slide Valve which was manufactured from cast iron and gunmetal, allowing for it to be used at a pressure up to 200 lb/in2. By the 1890s these had been improved to work at pressures up to 250 lb/in2, partly by the use of cast steel in their manufacture. By 1889 the company was also producing the Accessible Check Feed Valve, which allowed the valve and seat to be examined while the boiler was under steam, and the Absolute Water Gauge, which automatically prevented the escape of steam and water in the event of a broken gauge glass.

March 1894 saw the company transformed into a private limited company, with an initial capital of £40,000. This new company took over the entity of the previous one and operated under the name of J. Hopkinson & Co Ltd. Under this new organisation it would continue to improve its equipment, producing the Hopkinson’s Centre-Pressure Valve in 1903, which was designed as a turbine stop valve. At the same time the company would begin preparations for a new site in Birkby, later to be know as Britannia Works. When this opened in would employ 600 people.

In 1904 the company would enter into an association with Dr Sebastian Z. de Ferranti. As part of his work he would combine the feature of a venturi flow meter with a parallel slide valve to produce a valve with a converging inlet and diverting outlet flow. This would be developed into the Hopkinson-Ferranti Stop Valve, which had the major advantage of being much easier to operate than full bore valves.

By 1910 the firm had depots and showrooms in 30 cities worldwide. The First World War would see many of their employees joining the military and production would concentrate on essential war materials. Following the end of this conflict a new company, operating under the name of the old one, was formed to take over the activities and assets of J. Hopkinson & Co Ltd. This new institution would have a starting capital of £600,000.

In 1924 J. Hopkinson & Co Ltd would exhibit at the British Empire Exhibition at Wembley. This coincided with their 80th anniversary and as a result an excursion of 1,300 employees and their relatives was organised to travel from Huddersfield to Wembley.

1930 would see the company produce a 10 inch centre pressure turbine stop valve for Delray No 3 Power Station. This was designed to operate at 415 lb/in2 and 1,000oF, and was notable for being the first time the company produced a valve using alloy steel. The increase in operating pressure the company’s valves were capable of would continue to increase throughout the 1930s and by 1936 it would produce one of Brimsdown A Power Station which operated at 2130 lb/in2.

During the Second World War the company was given a high priority as their products were used in government factories, as well as being vital for the continued operation of power stations and other industrial plants. Beyond this it was involved in the production of components for armaments, aircraft, tanks, and ASDIC. Following the war the modernisation of the country’s electrical industry’s infrastructure led to great increase in the number of orders placed with Hopkinson’s. In 1956 the company would produce equipment for commercial and experimental nuclear reactors, including the newly opened Calder Hall power station. The made great use of the venturi valves, developed in cooperation with Ferranti from 1904, as they could closed in 2 seconds, as opposed to 5 minutes for earlier designs of valves.

In 1966 the company would change its name to Hopkinson’s Limited, although it would continue to operate at the same site. During the 1980s it would form a number of subsidiaries, including a repair and servicing one in Cardiff. In 1988 Blakeborough Control Valves would be incorporated into the Hopkinson’s range.

In 1989 Hopkinson’s Limited would cease to operate as an independent company when it was bought by the Weir Group. Despite this it would continue to manufacture valves, even expanding into oil and gas pipeline valves in 1993. In 2002 the Weir Group would reorganise forming Weir Valves and Controls, of which Hopkinson’s would be a part. This would be sold to Trillium Flow Technologies in 2019.