Size Selection and Accessories

Pump Size Selection. - First you must establish if you will column lift or draft.

Less than 8 meters
Column lift is simply putting the hose completely in to the water and lifting a column of water in to the tank. To explain atmospheric pressure 101.3Kpa will push against the liquid and as the vacuum pump has created a lower pressure in the tank the water will flow in to the tank. A column lift is fast and efficient but is limited to about 8 meters of water height difference. This is because the weight of the water becomes heavy enough that it equals force created by atmospheric pressure so even with a perfect vacuum the liquid would not flow after this height is reached. For column lifting it is important to have a pump that is capable of around 27'Hg. Air flow is normally sized on the tank size as this determines evacuation time. Flow rates up to 400CFM are common, the standard septic tank contractor has a flow of 230CFM.
Pumps - Masport HXL pumps and WR pumps are great for column lifting. Up to 400CFM

More than 8 meters
Drafting suspends the product in a fast moving air stream. This is achieved by letting enough air into the pipe to carry the product to the tank. If enough air speed can be maintained lifts of 30+ meters are possible. The key to drafting is having a pump with enough flow to maintain a high air speed. Flow rate is determined by the air speed required to suspend the product and cross sectional area of the pipe. Larger pipe sizes can be a lot faster but require a lot more air flow to maintain the air speed. The vacuum pressure is less important.
Pumps - Finder Liquid rings, or NVE / Hibon roots blower.

Vacuum Truck Components

Manways
Pre-filters
Primary traps
Secondary traps
Oil-separators
Exhaust oil-catch mufflers
Silencers
Exhaust interceptors
4-way valves
Gauges
Relief valves, pressure and vacuum
Swing check valves
Hose adaptors
Odour eliminators

Masport Accessories Brochure

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