The Milwaukee 49-16-19PS 4-Gallon Sprayer Tank Assembly w/ SWITCH-TANK is an interchangeable sprayer tank made for users who already run the Milwaukee M18 Powered Base w/ SWITCH TANK system. This is a sprayer tank assembly designed for applying liquid treatments with the compatible powered base, not a complete standalone sprayer. Model Number: 49-16-19PS. If you need a dedicated tank for a specific chemical or application, this setup lets you keep jobs organized and spend less time cleaning between them.

The big reason this tank matters is system flexibility. Milwaukee built it as an add-on tank assembly so you can keep separate tanks ready for different treatments and avoid cross-chemical contamination. That is a real-world advantage for anyone handling multiple liquids, because it cuts down on tank changeover time and helps keep one application from carrying over into the next. Easy-access latches are part of that workflow, so swapping tanks is quicker and more practical on the job.

Control is another strong point. The system is built around instant, constant, and adjustable pressure, which gives the user more predictable spray performance instead of the uneven output you get when a setup struggles to maintain pressure. Milwaukee rates this tank assembly at up to 140 psi with a vertical spray distance of up to 24 ft. In plain terms, that means the tank is built to support both close, controlled application and longer reach when the job calls for it.

Milwaukee also paid attention to the parts that take the abuse. The dual diaphragm pump is there for longer pump life, and the critical Viton seals are used for improved durability against harsh chemicals. Those are not throwaway details. If a sprayer is going to be used regularly, the pump and seals are exactly where durability matters, and this design focuses on those wear points.

From a handling standpoint, the 4-gallon capacity gives you useful volume without turning the assembly into an oversized tank that is awkward to manage. The wide mouth opening makes filling easier, the strainer helps keep debris out of the tank, and the high-visibility markings make it easier to keep an eye on fill level. Milwaukee also includes tank identification stickers and an onboard measuring cup, which are small details that make more sense the more often you use the system.

Compatibility is straightforward: this tank assembly is designed to work with the M18 Powered Base w/ SWITCH TANK (3019-20), which is not included. The included pump, hose, wand, and nozzles make this a functional tank assembly, but it still depends on that powered base to operate as intended. If you are already on the Milwaukee M18 platform and using the SWITCH TANK system, this is the clean way to expand your setup.

The Milwaukee 49-16-19PS 4-Gallon Sprayer Tank Assembly w/ SWITCH-TANK makes the most sense for users who want one powered base with multiple dedicated tanks instead of one tank doing every job. That includes crews handling recurring property treatments, grounds work, and exterior spraying where organization, chemical separation, and quick changeovers matter. If you need the base too, plan for that up front. If you already have it, this is the part that makes the whole system more useful.

Milwaukee 49-16-19PS 4-Gallon Sprayer Tank Assembly w/ SWITCH-TANK Makes the System Worth It

This is the kind of add-on that makes a modular sprayer platform actually practical, especially if you want separate tanks instead of one tank doing every job badly.

• Who it's for: Users already running the M18 Powered Base w/ SWITCH TANK who want a dedicated 4-gallon sprayer setup for recurring exterior and property-treatment work.
• Why it stands out: The interchangeable tank design, adjustable pressure, dual diaphragm pump, and Viton seals all solve real use problems, not brochure problems.
• Worth knowing: This is not a complete standalone sprayer. You need the compatible powered base, so it makes the most sense if you are already bought into the SWITCH TANK platform.

• Does this work by itself? No. It is powered by the Milwaukee M18 Powered Base w/ SWITCH TANK (3019-20), which is not included.
• What is the tank capacity? The tank holds 4 gallons.
• What is the maximum pressure? Milwaukee lists a maximum pressure of 140 psi.
• Why use a separate tank assembly? Milwaukee designed it so users can add tank assemblies for different applications and help eliminate cross-chemical contamination.