NW Conversions 20 Gallon Wheel Well Water Tank - Left (SP-L-20)

Lightest tank in the wheel-well range at 22 lb dry, offset for the driver side.

The SP-L-20 sits to the rear of the wheel well on the driver side — the space that usually ends up as a dead corner behind the galley. Forty-five inches long, 12.5" deep, and at 22 lb dry it is the easiest tank in the family to handle single-handed while you work out the mounting.

It can physically be placed on either side; on the passenger side the same shape lands in front of the wheel well instead of behind it. Most builders still buy the side-specific version, because the pump plumbing ends up shorter.

Should you buy this tank, or a different one in the range?

• Buy the SP-L-20 if your tank is going on the driver side and you want the lightest, easiest-to-mount option.
• Buy the SP-R-20 for the passenger-side equivalent.
• Buy the SP-C-20 if you would rather straddle the wheel hump than sit beside it.
• Step up to the SP-L-33 if you need capacity more than you need a light tank.

Confirmed fitment

Transit wheel wells are slightly smaller than Sprinter wheel wells, so a Transit install leaves extra room around the well. Fill it with closed-cell insulation rather than leaving an air gap.

Specifications

The 1/2" port at the bottom of the open end is the one to use for pump suction — it drains the tank furthest down. These tanks are not pressure vessels. They must be vented to atmosphere — a sealed tank will balloon on a hot day and collapse inward when the pump draws it down.

What ships to you

• (1) SP-L-20 20 gallon rotomolded tank
• Fittings, hose and mounting hardware sold separately

Installing it: what actually happens

Use the low 1/2" port on the open end as your draw. Plumbing the suction from an end port higher up leaves two or three usable gallons stranded in the bottom of the tank, which people only discover on the third night of a trip.

At 22 lb dry you can hold this one in position yourself while marking the strap lines, which makes the dry fit genuinely quick.

• Draw from the low 1/2" port on the open end.
• Bench-drill any 1.5" ports you intend to use; the 1/2" ports are already open.
• Support along the full 45"; two straps into floor anchors.
• ProMaster: a 3.5" riser built into the subfloor.

Questions we get asked about this part

Do I have to drill the ports myself?

On the wheel-well tanks the 1/2" NPT ports arrive open and ready to thread. The 1.5" ports are spun closed at the factory so you only open the ones your plumbing actually uses. Open them with a hole saw on the bench, before the tank goes anywhere near the van, and vacuum the shavings out. Plastic chips inside a fresh water tank are a mistake you only make once.

Does the tank need a vent?

Yes. It is designed to run unpressurized. Run a vent line from the top 1.5" port up above the maximum fill level and out through the floor or a body vent. Skip it and the tank will deform on a hot day, then pull its walls in when the pump runs.

How much weight am I adding to the van?

Water weighs roughly 8.34 lb per gallon, so 20 gallons is about 167 lb of payload once full, on top of the dry weight of the tank. Put that number in your build budget before you order rather than after — it is the most commonly forgotten figure in a van conversion.

Can I run this as a grey tank?

Yes. If you do, use the low end port as the dump outlet, add a ball valve you can reach from outside, and leave yourself a way to flush it. Grey tanks smell when they cannot be rinsed.

Pairs well with

• Van water tanks and plumbing — the rest of the NW Conversions range

Sold and shipped by Campervan Parts R Us, the parts counter of Noke Van Co. — a working van conversion shop in Roanoke, Virginia. If you are unsure whether this fits your van, email us the year, model and wheelbase and we will check it against a build sheet before you order.