Vents

TITLE:

A light and simple, air operated vapour vent with 90mm nominal diameter outlet and Sequential air actuation.

PURPOSE:

To allow venting of vapour from tank compartments while loading or unloading.

OPERATION:

Operated by a piston, the poppet opens inwards to prevent leakage from product surge. The sequencing valve is offered to ensure main poppet is fully open before next vent opens. The end signal can then be used to provide a permissive signal for loading/unloading in the certainty that all vapour vent poppets are open. The sequencing valve can be blanked if not required.

ADJUSTMENT:

None required

MATERIALS:

Aluminium body
Acetal piston and viton seals.

MOUNTING:

Mounts directly on to Liquip manhole covers or by weld flanges in aluminium, steel or stainless steel for walkway and coaming mount.

WEIGHT:

1.9 kg

TECHNICAL DATA:

Operating pressure 120kPa to 900kPa (normal 500kPa)
Consumption/stroke 1 litre free air.
Main poppet opens at 120kPa
Bolted to manhole or flange by bolting from underneath.

ASSOCIATED EQUIPMENT:

VRB3.5-1 & 2 - Weld stub to allow venting into coaming (aluminium & mild steel)
Mounting flanges in aluminium, mild steel & stainless (variations shown below)
AVV3-12 - Polyurethane louvre for weather & anti-spark protection
AVV075VW with through holes for mounting.
AVV175VAT chemical version
Spark Arresting Gauze (optional).
Stainless steel version available, AVV3SST

TITLE:

A chemical resistant, air operated vapour vent with 90mm nominal diameter outlet. Sequential air actuation.

PURPOSE:

To allow venting of vapour from tank compartments while loading or unloading.

OPERATION:

Operated by an piston, the poppet opens inwards to prevent leakage from product surge. The sequencing valve is offered to ensure main poppet is fully open before next vent opens. The end signal can then be used in the certainty that all vapour vent poppets are open. The sequencing valve can be blanked if not required.

ADJUSTMENT:

None required

MATERIALS:

Stainless steel body, grade 316.
Stainless steel trim (grade 316) with teflon encapsulated seals.

MOUNTING:

Mounts by weld flanges in aluminium, steel or stainless steel.

WEIGHT:

3.7 kg

TECHNICAL DATA:

Operating pressure 70kPa to 900kPa (normal 500kPa)
Consumption/stroke 1 litre free air.
Main poppet opens at 7kPa
Bolted from outside into top of blind tank flange.

ASSOCIATED EQUIPMENT:

Mounting flanges in stainless steel (shown below) to CEN 13082:1987
Spark Arresting Gauze, AVV3SS-11.

TITLE:

Pressure & vacuum relief for road tankers incorporating rollover protection.

PURPOSE:

To provide pressure and vacuum relief to Australian Standard AS2809 for road, rail & storage tanks. They provide more capacity than the standard PVV104, which deals with thermal effects on the tank. Rollover protection is designed in and locks shut at any angle greater than 60° from the vertical.
These vents are used on storage & blending tanks. It is important that the pressure/vacuum volume of the tank is known so that the correct size & number of vents can be supplied.

OPERATION:

There are three separate poppets in the PVV204 assembly.
The pressure poppet only opens when the internal pressure of the tank exceeds the setting shown below.
The vacuum poppet only opens when the internal pressure of the tank falls below the setting shown below.
The rollover poppet is always open except when tanker is on an angle greater than 60° from vertical.

ADJUSTMENT OR SERVICE:

Check seals periodically for wear and replace if necessary

MATERIALS OF CONSTRUCTION:

Aluminium body & poppets (316 grade stainless also available)
Stainless steel housing, shafts and springs
Nitrile seals (teflon seals also available)

MOUNTING:

May be mounted onto VOH manholes or on a separate weld flange

WEIGHT:

TECHNICAL DATA:

NSW Dangerous Goods Branch Approval No N 3554 Q
Gas capacity 240m³/hr free air at 35kPa
Max recommended liquid loading rate 1000 litres/min

TITLE:

Pressure & vacuum relief vent for road tankers incorporating roll-over protection.

PURPOSE:

To prevent the build up of pressure & vacuum caused by expansion, contraction and tanker movement.

OPERATION:

The PVV range of vents as listed below, are mounted inside the tank either on the manhole or on a separate flange. There are various designs, but all allow excess pressure & vacuum to be equalised through a gauzed flame proof opening and all have roll-over protection ensuring compartment is sealed if tilted more than 60° from vertical.

TECHNICAL DATA:

VARIANTS:

PVV104 & PVV104U. PVV104 is identified by the free air bleed hole in the body. PVV104U has no bleed hole and a very distinctive full circle marker groove around the body.

WEIGHT:

0.6kg.

MOUNTING:

Specify where the vent is to be mounted
ie (i) on VOH400 series hatch
   (ii) on VOH200 & VOH700 series hatches
   (iii) on SH300 series swing back hatches
   (iv) on remote weld flange
& Liquip will supply the complete kit

MATERIAL OF CONSTRUCTION:

Aluminium body & poppets.
Stainless steel springs.
Bonded nitrile seal.
Nylon coated bronze ball.

TITLE:

Medium capacity vents 50mm nominal bore used primarily for storage tanks.

PURPOSE:

Spring operated separate pressure and vacuum vents with gauzed exits. Cuts down contamination of product in storage tank and vapour loss from volatile liquids. Easy to clean and maintain.

MOUNTING:

Mounted on to tank by weld flange, or in some circumstances, can be bolted directly through tank top.

TECHNICAL DATA:

Vacuum vent open 3kPa allows discharge rate of 2000 l/m at 10kPa vacuum.

TITLE:

Medium capacity vents 50mm nominal bore used primarily for storage tanks.

PURPOSE:

Spring operated separate pressure and vacuum vents with gauzed exits. Cuts down contamination of product in storage tank and vapour loss from volatile liquids. Easy to clean and maintain.

MOUNTING:

Mounted on to tank by weld flange, or in some circumstances, can be bolted directly through tank top.

TECHNICAL DATA:

Pressure vent opens at 15kPa, capacity 430m3/hr free air at 35kPa. Allows loading rate of 1500 l/m at 21kPa tank pressure.

TITLE:

Pressure vent for storage tanks.

PURPOSE:

To limit excess pressure within a tank to 30kPa max.

OPERATION:

When welded into tank shell, a Ø100mm opening is held closed by a spring within the tank. When the pressure reaches a pre-determined level (typically 30kPa), a poppet opens and vents the excess pressure to atmosphere. The vent closes and seals at pressures lower than 30 kPa.

DISMANTLE:

From inside tank, remove nyloc nut, spring and 2 flat washers and lift poppet out.

ADJUSTMENT:

None.

VARIATIONS:

There are several different variations using combinations of aluminium, mild steel, stainless steel and 316 grade stainless steel together with either buna nitrile, viton or teflon encapsulated o-rings. Also special opening pressures can be supplied.

WEIGHT:

TECHNICAL DATA:

Vent opens at 30kPa
Capacity 3250m³/hr at a pressure of 45kPa
Conforms to AS2809-1985