Blowers and pumps both have benefits, but apples to apples, only one is right for your vacuum truck.
Now that the busy season is behind you, it might be a good time to think about upgrading your vacuum truck fleet. You probably have a chassis and tank in mind, but what about the pump? Should you go with a rotary vane pump or a positive displacement (PD) blower?
At their most basic level, PD blowers and rotary vane pumps both create negative pressure. Blowers use twin rotating rotors to displace air inside a tank, while rotary vane pumps compress air to create a void. When the load valve is opened, atmospheric pressure pushes debris up the hose and into the tank.
So how do you know if a pump or blower is right for you? Before deciding, first determine what you plan to pump.
Will you be using the truck for industrial dry material handling, hydroexcavation or sewer cleaning? Those jobs call for greater cubic feet per minute (cfm) and are best suited for blowers. For most other jobs, a rotary vane vacuum pump will do just fine, especially when it comes to cleaning portable restrooms.
Know the specs
Phil McKee, president of Vacutrux, the Canadian-based vacuum truck manufacturer and distributor for Dresser Roots blowers as well as Wallenstein and Robuschi pumps and blowers, says blowers should be considered if you plan to clean catch basins, car wash pits and peat moss-based septic systems.
“A septic pump operator doesn’t need 1,000 cfm, 1,500 or 2,000,” he says. “But if you have other uses for that truck, by all means go for the big cfm and go for a blower.”
Another factor to keep in mind is hose size. The larger the hose, the harder it becomes to maintain negative pressure inside the tank. Depending on the material being pumped, greater cfm often is needed.
“If we’re talking about 6-inch and 8-inch loading arms or hoses, this is where the PD blower really shines,” McKee says. “Beyond a certain size, which we believe is 1,000 cfm, a blower is the only thing you want to use.”
What’s your bread and butter?
But if portable restrooms and septic systems are your bread and butter, a vane pump might be your best choice.
One option is the Jurop RV360 rotary vane vacuum pump from Jurop/Chandler offers efficient dual-fan cooling technology and quiet operation. It requires an input of 1,100 to 1,300 rpm and creates output of 360 cfm (332 cfm at 18 inches Hg), and produces a maximum pressure of 30 psi.
Pumps are built for abuse and are less costly to repair. Many last 10 to 15 years. If you’re ready to invest in a long-lasting pump, check out these heavyhitters:
The PM2000 Storm Series liquid-cooled vacuum pump from Moro USA is capable of pumping nonvolatile liquids and sludge from long distances, providing an additional choice for heavy-duty industrial applications with a tank capacity of 3,000 to 6,000 gallons.
The General Pump MW Series offers five plunger sizes to cover flow ranges from 36 to 105 gpm and pressures up to 4,350 psi. It also features a movable gearbox with three ratio options, including an available SAE C hydraulic “plug and play” for hydrostatic drive units.
The HXL400WV heavy-duty, water-cooled pump from Masport is designed for septic pumping use. It is capable of airflows up to 400 cfm and 25 inches Hg continuous duty for vacuum, suitable for tank sizes in the 2,500- to 4,500-gallon range.
The Berringer liquid ring pump unit from Keith Huber Corporation provides 1,000 cfm of vacuum and high-velocity air induction with a pressurized push-button tank discharge.
The Bolt and Go from Surpresseur 4S features a range of Robuschi RB-DV 28-inch HgV high-vacuum blowers from 500 to 2,600 cfm.
The 753 Series vacuum pump from Wallenstein Vacuum Pumps incorporates extra-wide vanes that allow up to an inch of wear, resulting in longer service life with lower maintenance costs. It provides 422 cfm airflow performance at 1,200 rpm operation and precision machining for vacuum levels up to 28 inches Hg.
Conde Powerpak preassembled, gasoline- or diesel-powered vacuum pump units from Westmoor Ltd. are easily installed by bolting and attaching them to the tank.
A blower, however, can be easily damaged by liquids or solids because of the close tolerances of its internal components. Blowers can be costly, difficult and time-consuming to repair, often taking weeks to put back into service.
And then there’s the noise factor. Blowers are noticeably louder than pumps.
“In the portable toilet world and septic world, you don’t want the decibels these things put out,” McKee says. “A vane pump can stealthfully sneak into a residential area, special event, construction site or park, do its job and sneak away. It’s hard to do that with a blower because of the high rpm and high pitch.”
Maintain and protect
Whatever you decide, keep your equipment maintained. Blowers especially require protection from overheating.
“A 30 hp rotary vane pump will clean a lot of septic tanks and not approach a critical heat level,” McKee says. “Whereas a 350 hp PD blower, you’re at full vacuum and working the pump extremely hard.”
Of course, some jobs leave you no choice. When it comes to large cfm and big loading hoses, PD blowers are the only way to go. Here are some of the latest blowers available today:
KAY Blowers from BRUDON Air Vac / Kay International have a robust housing design and an impeller profile that reduces pulsation, noise and slippage.
VTB or SIAV Series blowers from Hibon Inc. (a division of Ingersoll Rand) produce high vacuum levels and are not limited by the heat generated inside the blower.
The Challenger 4310 high-vacuum, positive displacement blower from National Vacuum Equipment delivers 940 cfm and is capable of running at 27 inches Hg continuous vacuum.
“It’s a fantastic improvement over liquid ring and other types of vacuum generators,” McKee says. “But if you don’t need to use a PD blower, why would you?”
Need pump accessories? Check out these options:
- Lamitex vacuum pump vanes from Franklin Fibre are tested composites for North American- and European-manufactured pumps in light- to heavy-duty demands at temperatures up to 350 degrees F.
- Fruitland Green biodegradable vacuum pump oil from Fruitland Manufacturing can be used with all Fruitland rotary vane pumps. It is both environmentally and operator safe.