Safety Valves.

PRV pressure relief valve.

Basic and unconditionally required protective devices against overpressure, of working systems like installations or tanks are PRV. Broad range of solutions are designed, to deal with different: working medium (gases, dusts, vapours, semi-solid medium), range of rated pressure, constructional and many other specialist requirements. In order to a proper performance of PRV and a whole installation, a suitable selection must be conducted, as it influences environment and human’s life safety. 

Thus, a selection and an assembly with latter maintenance of PRVs should be performed only by qualified team. 

CORONA offers PRV designed by Anderson Greenwood & Crosby. All of them requires high relief standards. The PRV can be distinguished into groups: 


CROSBY’s pilot operated pressure relief valves.

Pilot operated PRV offered by Anderson Greenwood Crosby operates higher opening pressures than direct spring operated one - to this level, when one pilot operated PRV replaces successfully five direct spring operated ones. Due to replacing a spring (which holds valve’s seat in closed state), a height was limited. Pilot operated PRV are applicable in terrestrial and marine oil and gas processing industry (LNG, LPG, LIN, LOX), chemical industry and where low temperatures are required (cryogenic conditions). PRV opens itself when an overpressure occurs. Throttling of medium does not occur, what causes a freezing in cryogenic conditions

CROSBY’s JCE series process direct spring valves

CROSBY’s type JCE PRV comprises of disc, which is designed to always match the nozzle. It is manufactured in standard edition (when pressure deviation while releasing the medium do not exceed 10% set value), with compensating metal bellows (when a few valves release agent to collective tank or other, when pressure deviation while releasing is up to 40% set value) or be equipped with special disc, employed for liquid media (providing seamlessly performance). CROSBY’s JCE series process direct spring valves ensures full security against excessive pressure rise and low price of purchase and maintaining at the same time.

OMNI-TRIM type valves - 900

OMNI-TRIM type valves have a simple design. They provide against overpressure occurrence in installation of average medium flow rate, employed in refiners, chemical and petrochemical industry, in auxiliary power industry installations and in paper industry. Retardation of closure equals 20% or less of time set value. All parts are conventional, so an assembly is simple and device is durable, reliable and cost-efficient

60 and 80 series direct spring operated valves

Spring operated PRV 81 type are applied to protect many appliances in wide range of pressures and temperatures, to handle with gaseous and liquid media. It enables tightness even when operating near the pressure of opening. The seat is made of polymeric material 83 series valves’ seat are made of polimeric material as well and are suitable to employing in pressure installation of gaseous media, with low overpressure tolerance and to control expensive or contaminated gaseous products 61 series valves are suitable for gaseous installations, where low or medium opening pressure is required or to protect installation against hazardous thermal expansion. Brass casing is applicable in installations operating with CO2, Natural Gas or others.


CROSBY’s JOS and JBS type process direct spring valves are designed to protect against excessive pressure rise in installations of gaseous media (like air, vapours) or of difficult conditions (like in power energy industry). Valves are available in materials such as: Monel, Hastelloy, SST. JOS-E and JLT-JOS valves are employed to release excess of agent into air or to low-pressure outlet system. They are equipped with compensating metal bellows, which minimalize side-effects of overpressure releasing on the valves’ work parameters.


Emerson Crosby brand has maintained its leadership in overpressure protection. The direct spring-operated safety and pressure-relief valves PRV are among the world’s most widely used for oil and gas production and refining, petrochemical and chemical processing, and conventional and nuclear power. With the Crosby brand, Emerson maintains the industry’s most extensive high-flow facilities for valve testing in air, steam, and water.

CORONA, as Crosby’s authorized representative in Poland, offers wide range of protective units. We provide the designing stage – measurements and calculations, leading to an adequate performance.

We ensure a design and assembly with further servicing.