Question:
I’ve got a Boyd slide-in unit (100 gallons fresh/300 gallons waste) with a vacuum-only pump. I’d like to route the exhaust from the pump back into the tank to pressurize the tank, as some of the waste stays in the tank even when the front of the truck is up on ramps. Anyone else done this?
Answer:
If you have a vacuum pump, putting the exhaust into the tank will not pressurize the tank. You’ll be circulating the air and that’s all. You need a four-way valve installed on your pump.
Question:
I’m looking at stainless and aluminum slide-in vacuum tank units, both with 400-gallon waste/200-gallon freshwater configurations. They have the same pump and engine combinations, so what would you prefer and why?
Answer:
I have a stainless steel tank on my C5500, and you can’t beat stainless. It will last a lifetime. But if I were going to buy a slide-in unit I would buy aluminum. The main reason is the weight; aluminum is so much lighter. You could run a lighter truck under it.
But one word of caution: a tank that size should cover 20 to 30 restrooms a day, if you’re lucky. When I bought my tank, I figured seven gallons of freshwater per restroom and 10 to 15 gallons of wastewater. The 200-gallon freshwater tank you mention then will service 28 units, and the 400-gallon waste tank will allow you to service 20 to 30 units. If your business grows, this tank might not be big enough to serve your needs.
I don’t have a slide-in unit, but I would like to have one. I have an older service truck for a spare, and a pickup truck. If I had a slide-in unit, I could get down to one pickup as a spare and reduce my insurance premiums. However, I own my two backup trucks outright, and the payment on a slide-in unit isn’t justified.
