For really tight spaces and to minimize piping to the bare minimum, Armstrong Dual-Arm Pumps are the only way to go.
The Dual-Arm pumps boast all of the same benefits of the single Vertical Inline pumps but to a higher degree.
A Dual-Arm pump is a two pump assembly with one volute. They can run main and standby or in parallel. The volute has a swing discharge port to hydraulically separate the casings to prevent recirculation when only one pump operates. One pump can also be fully isolated for maintenance while the other is still fully operational.
Have the absolutely lowest footprint available in the market and fit in spaces previously not possible.
Get even more installation cost savings. Eliminate an entire piping run for the second pump. That includes pipe insulation, painting, etc. Eliminate a whole set of valves, strainers, supports, and inertia bases too.
Double your installed savings, half your required space with Dual-Arm pumps.