Daiwa Hanbai Corporation Ltd.|High velocity pressure/vacuum valve (Pres-Vac Engineering)

High velocity pressure/vacuum valve (Pres-Vac Engineering)

High velocity pressure/vacuum valve (Pres-Vac Engineering)


The PV-ECO and the PV-VOC are designed based on the experience gained by Pres-Vac over the last 60 years. They are designed using the latest technologies but most importantly, the PV-ECO and PV-VOC are designed based on customer feedback. The PV-ECO and PV-VOC are designed on the same platform, but have widely different performance characteristics, enabling customers to use the two valves for different applications. The PV-ECO is designed for use on Chemical Carriers and Product Carriers addressing the special requirements for P/V valves while the PV-VOC is designed to meet the requirements that larger Crude Oil Carriers have for P/V valves. The PV-VOC is furthermore designed to reduce the amount of cargo vapor by implementing a special 2-step opening sequence. The valves are in compliance with all latest IMO regulative and European Marine Equipment directive, MED including EN ISO 16852:2010 as a new standard for testing of flame arrestors to be installed on-board marine vessels.

>PV-ECO/PV-VOC Pressure Valve Zoom

The PV-ECO pressure valve has an advanced patented flow control design securing that the valve has a soft opening and closing phase securing efficient operation also at low flow rates. A patented integrated dampener secures that the valve can operate non-hammering and non-oscillating on long pipes.
The PV-VOC pressure valve is designed for optimized VOC performance and are based on same flow control design as the ECO valve. The two-step opening secures that the opening and closing pressure is kept at the same pressure level during breathing phase (approximately about 50% of total flow capacity). This feature contributes to lowering VOC emission in all stages in the operation of an oil tanker.
Both the PV-ECO and PV-VOC is designed to minimize noise during operation. Optimized nozzle design has reduce noise level by 10-15dB compared to other designs. Both valve type can be supplied with optional replaceable resilient seal in pressure seat reducing leakage to almost nil leakage. The optional resilient seal reduces disc/seat wearing.
PV-ECO/VOC Vacuum Valve

>PV-ECO/VOC Vacuum Valve Zoom

The vacuum valve is designed to avoid excessive under pressure in the cargo tank during discharge operations.
When the tank vacuum exceeds the preset opening setting the valve will open and let air into to the tank. The valve size is carefully selected from the pump capacity (discharge rate) and VECS operations. The vacuum valve is also used as breather valve during voyage.
Gas Freeing Cover

>Gas Freeing Cover Zoom

Gas freeing onboard tankers is required for entry into cargo tanks, hot works, and inspection or washing for clean ballast tanks.
Before a cargo tank can be gas freed it is required to purge the cargo tank with inert gas until the hydrocarbon gas content is below 2% by volume, in order to ensure the tank atmosphere is not in the flammable range.
Venting of toxic and flammable gas during gas freeing should be through the vessel's approved gas freeing outlets, and therefore the exit velocity should be minimum 20m/s to carry the vapors clear of the deck.
We provide both vacuum integrated gas freeing covers type as well as separate gas freeing covers approved for both IIA and IIB cargo groups.
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