Vacuum trucks

Some liquids might create an ignitable froth layer (5-1.3.1), although mist accumulation will be offset under conditions where there is periodic suction of air through the hose, it is possible to specify a vacuum tmck tank with MAWP 50 psig, sufficient to contain a deflagration beginning at up to 

At the time of writing, API Publication 2219 Safe Operation of Vacuum Trucks in Petroleum Service was in preparation. 

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API Publ 2219, Safe Operating Guidelines for Vacuum Trucks in Petroleum Service, 1st ed., September 1986... 

Service company wastes such as empty drums, drum rinsate, vacuum truck rinsate, sandblast media, spent solvents, spilled chemicals, and waste acids... 

Vacuum truck and drum rinsate containing nonexempt wastes... 

Drilling muds are fluids that are pumped into the bore holes to aid in the drilling process. Most are water based and contain barite, hgnite, chrome lignosulfate, and sodium hydroxide [11], but oil-based drilling muds are still used for economic and safety reasons [12]. Used muds can be removed by vacuum trucks, pumped down the well annulus, or allowed to dewater in pits, which are then covered with soil or disposed of by land farming. 

Shinn et al. (1989) have investigated the removal of plutonium from surface soils at the N.T.S. by use of a vacuum truck of the type used to clean streets. Vegetation on the site comprised small shrubs giving 15% ground cover. This was cleared and two to five cm of soil was then removed by the vacuum truck. 

The equilibrium vapor pressure above a confined liquid depends only on temperature. The fraction of the total pressure exerted by vapor pressure determines the composition of the vapor-air mixture. Thus when the total pressure is reduced, for example at high elevations or in vacuum trucks, the vapor concentration in air increases. Since flash points are reported at a... 

A transfer vessel is a device that receives the contents of another vessel for emergency or nonemergency purposes. It can be as simple as a vacuum truck or as complex as a hard-piped, dedicated system. For liquids, the system typically consists of a container or containment system located below the protected vessel where gravity will promote a rapid transfer. In the few instances where a transfer vessel is used with gases, it assists in the depressurization of a process. In other instances, it may consist of a spare vessel capable of accepting the contents of a nearby vessel (in case of fire or leak) so that the damaged vessel s entire contents are not destroyed or released (Lees, 1980). In this case, a pump may be used to make the transfer between vessels. 

Changes made to compensate for unavailable or out-of-service process equipment, instruments, rotating equipment, or vessels, such as using jumpovers, hoses, and vacuum trucks, without established SOPs. 

FiGune 9-12 A collapsed service company vacuum truck signals an inadequate mechanical integrity program. 

Suction or vacuum skimmers use a vacuum or slight differential in pressure to remove oil from the water surface. Often the skimmer is only a small floating head connected to an external source of vacuum, such as a vacuum truck. The head of the skimmer is simply an enlargement of the end of a suction hose and a float. The principle of operation of a suction skimmer is shown in Figure 23. 

Suction skimmers are similar to weir skimmers in that they sit on the water surface, generally use an external vacuum pump system such as a vacuum truck, and are adjusted to float at the oil-water interface. They also tend to be susceptible to the same problems as weir skimmers. They are prone to clogging with debris that can stop the oil flow and damage the pump. They also experience the problem of rocking in choppy waters that causes massive water intake, followed by air intake. Their use is restricted to light to medium oils. 

As all skimmers recover some water with the oil, a device to separate oil and water is usually required. The oil must be separated from the recovery mixture for disposal, recycling, or direct reuse by a refinery. Sometimes settling tanks or gravity separators are incorporated into skimmers, but separators are more often installed on recovery ships or barges. Portable storage tanks are often used as separators, with outlets installed on the bottom of the tanks so that water that has settled to the bottom of the tank can be drained off, leaving the oil in the tank. Vacuum trucks are also used in this way to separate oil and water. Screens or other devices for removing debris are also incorporated into separators. 

Photo 135 This spill is being recovered with pumps and a vacuum truck. (Environment Canada)... 

Suction hoses, pumps, vacuum trucks, and certain skimmers and sorbents, both natural and synthetic, are generally effective in removing excess oil from the surface, especially from ditches or low areas. The use of sorbents can complicate cleanup operations, however, as contaminated sorbents must be disposed of appropriately. Sorbents are best used to remove the final traces of oil from a water surface. Any removal of surface or vegetation also entails replanting and fertilization. 

This type of valve has given very good service in transfer and loading operations in 3-inch and 4-inch sizes. It has also been used satisfactorily in 4-inch and 6-inch sizes for vacuum truck service. Another example of its use is in catalytic-polymerization imit piping operating at 1,000 psig and 400° F. 

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