Alpha 13 Gallon Black Water Tank & Universal Fittings Kit FAQs

Asked by McDougald, from Hudson, FloridaAsked on April 10, 2026Answered by Elkhart RV Parts

Customer Question

Does the 13-gallon Alpha black water tank (SKU: 932BLANK) come with a pre-installed 3" drain pipe? Can I connect it using spinweld fittings, and is the Universal Holding Tank Fittings Kit (SKU: ERVP-HOLDINGTANKKIT) suitable? Are any holes pre-drilled in the tank? Does your spinweld fitting service apply to sensor installation? Finally, which RV toilet mounting flange should I use for a low profile gravity toilet mounted above this tank, and do flanges bolt on or require spinwelding?

Expert Answer

The Alpha 13-gallon black water tank (SKU: 932BLANK) is supplied as a blank tank without any pre-installed 3" drain pipe or pre-drilled holes, allowing full customization for your installation. To connect the 3" drain, you will need to spinweld a polyethylene coupler since the tank is made from polyethylene; ABS fittings are not compatible with spinwelding to poly tanks. The Universal Holding Tank Fittings Kit (SKU: ERVP-HOLDINGTANKKIT) is fully compatible and includes 3" and 1.5" couplers along with sensors, making it ideal for your installation needs. Our professional spinweld fitting service can also install the four sensors for you, ensuring precise placement and secure connections. For mounting your low profile gravity RV toilet above the tank, we recommend a standard RV toilet mounting flange that bolts on; these typically do not require spinwelding. If you need specific flange product recommendations or assistance, we can provide suitable options matched to your toilet and tank setup.