23-01-2013, 10:53 AM
INSTALLATION MANUAL FOR TANKER EQUIPMENT
1INSTALLATION MANUAL.pdf (Size: 973.49 KB / Downloads: 264)
INTRODUCTION
This information is presented as a guide and must be used in conjunction with local legislation and standards, Owners’ requirements and Tank Manufacturers’ procedures.
When planning the equipment to be purchased, always design the fittings and layout so that a future conversion to bottom loading, vapour recovery and overfill protection will be a simple task. Much of this is a no-cost item, such as spacing outlet pipes within the API envelope and using 100mm diameter outlet pipes.
If bottom loading and vapour recovery are already standard practice, it is wise to consider future innovations in the design. These include features such as electronic dipsticks and sealed parcel equipment. Liquip will be glad to advise.
Manhole Covers
Manhole covers with dip points must have the dip point located along the centre line of the tank. Rotate manhole around the dip point to maximise clear walkway passage and direct the vapour vent outlet towards the roll-over coaming. Similarly, ensure the overfill probe wiring duct will lie neatly into the same area.
Manhole covers and other equipment are normally sited on the kerb side (near/passenger side) of the walkway leaving a clear path along the offside (driver’s side) of the walkway.
Vapour Vents (Vapour Valves)
Vapour vents must be sited as near as possible to the compartment centre line to avoid problems when the tanker is not on a level surface. Vapour vents should never be sited adjacent to a bulkhead or too far to the left or right across the tank.
The pipe piece welded into the roll-over weld-ring of the tank should be inclined down towards the vapour vent approximately 5 degrees.
Pressure & Vacuum Vents (P&V)
All manhole hatches can be supplied with 1 off PVV104 / PVV104U or 1 off PVV204 / PVV204U vent.
Roll-over protection is built into the pressure and vacuum vent. A poppet completely seals off the vent if it reaches an angle of 60 degrees or more from the vertical. Flame proofing is provided by stainless steel gauze.
The PVV204 series vents are designed for use on tankers which load or discharge at less than 500 litres/minute without any other free to air openings.
The PVV204 provides more capacity than the standard PVV104, which accommodates only the thermal effects on the tanker. Roll-over protection is designed in and it locks shut at any angle greater than 60 degrees from vertical.
Overfill Protection System
Overfill Protection Probe
When installing the probe in the VOH200-5 housing on the manhole cover, it is essential that from the probe actuation point (trip point) there is at least 230 litres space remaining to allow for the normal delay in slow stopping. After setting, mark the probe body or extension so if replacement is required the new probe can easily be set to the required position. LDP probes have an extension with a scale engraved along the side to allow the set height value to be marked on the safe fill plate.
All electrical wiring should be in water-resistant and UV stabilised conduit and junction boxes. (Refer Tech Talk 37 IP66 min)
When using the PJB301 probe housing it should be sited on the walkway as close to the centre of the compartment as possible.