All photos courtesy Kevin Misley
Editor’s Note: This story first
appeared in The Edge,
member publication of
the Northeast Spa and
Pool Association.
It has been said many times that the circulation system is the
heart of a pool or spa.
Installing and maintaining
pool plumbing systems requires a
thorough understanding of plumbing
principles. Technicians must know how
to correctly connect pipes, fittings and
valves to ensure proper water flow,
circulation and pressure. They must
also be able to identify and address
potential issues before they lead to
significant breakdowns.
Grasping the fundamental plumbing
concepts enables technicians to identify
the source of problems and implement
effective solutions. For those with
experience, this article will be a reminder
of best practices. For newer hires, it’s a
great starting point toward proper habits.
THE STARTING POINT
It starts by performing the proper
calculations to match pump size with
piping size. With that knowledge, you can
establish a material list for your project.
The list should include, but not be limited
to, digging tools, pipe cutting tools, pipe
bending tools, tape measures, levels and
solvent cements.
The predominant pipe used in pool
and spa applications will be Sch 40
rigid PVC or Sch 80 PVC pipe. In some
cases, CPVC pipe or fittings will be
used. Both Sch 40 and Sch 80 fittings
are interchangeable; the only difference
between them is the inside diameter.
Sch 80 has a smaller ID and is a thicker
pipe than Sch 40. Sch 40 pipe is white
in color, and Sch 80 is gray. Be aware
that the electrical conduit is also gray
and should not be confused with the
Sch 80 water pipe.
Identifying and using fittings
specifically used for pressure
applications is paramount for pool and
spa projects and water features such
as fountains or waterfalls. The use
of DWV (drain water vent) fittings is
unacceptable. DWV is for non-pressure
plumbing applications only.
Many valves are used, but the most
common are CPVC diverter-type valves.
They can be equipped with motorized
valve actuators for remote operation.
Butterfly valves are commonly used
in large commercial applications. Ball valves and gate valves are other types.
Using the proper solvent cements is
essential, as certain cements have pipe
size limitations. It’s important to read the
labels and understand the differences.
Always use a PVC primer as it cleans and
softens the pipe and fittings by creating
a chemical reaction to allow PVC cement
to bond properly. This active ingredient is
called tetrahydrofuran.
PVC cleaners are available to
remove grease or oils from pipe and
fitting surfaces.
JOBSITE ESSENTIALS
Now that you have your list, you are
ready to head to the jobsite armed with
all your tools and a working plan for
your plumbing runs.
Upon arrival and review, you might
find some obstacles that can derail your
perfectly drawn pipe plans: buried gas
and electric lines, sewer lines, septic
lines, trees, tree roots, a storage shed or
a pool house.
Now, you must pivot and think
outside the box for your pipe runs.
This may include additional fittings or
some tricky pipe bending to go around
obstacles. It may increase your pipe run,
requiring you to revisit your hydraulic
calculations to ensure your change will
not affect the proposed performance.
Utility markouts are required by law
but only cover utilities and other buried
services in the front of the property.
Locating any of these items in the rear of
the property, where you generally work, is
your or your company’s responsibility.
I prefer to locate and pour a large
concrete equipment pad and arrange
and assemble the equipment before the
pipe runs. A large pad allows for ease of
future servicing.
Begin your trench excavation and
maintain a standard depth for your
piping. Generally, we dig 2 feet plus
to allow room for contractors coming
in after for such things as plants and
irrigation lines.
A bed of sand around 4 feet allows
you to level uneven sections and
protects the piping. You can begin
assembling your piping and head
toward the equipment set. The ends
of your pipe cuts must have a bevel of
between 10 and 22.5 degrees. This is
the ASTM standard (D2855-20 section
7.2 and 7.3).
The purpose of the bevel is to
ensure the pipe slides into a fitting
easily and also allows proper solvent
cement coverage on the pipe and
the fitting during assembly. Leaving
the sharp end on your pipe cut may
cause the cement to be “snowplowed”
toward the fitting, resulting in
adequate coverage on the pipe. There
are several manual beveling tools for
certain pipe sizes.
For buried pipe, we always use
colored glue for a quick visual
inspection. Our equipment sets always
use a clear primer and glue for a neat,
clean finish. Covering equipment with
cardboard and rags prevents glue drips
on the pad and the equipment. Always
wipe glue joints with a rag.
THE FINAL TOUCHES
Once you have completed all your
connections, you must pressure test
for integrity. The IPC/ISPSC (specifically
section 311.9 in the ISPSC) requires a
hydrostatic pressure test (use of water)
of 25 psi for 15 minutes. Per section
302.7, using compressed air on plastic
pipe is prohibited. Test plugs designed
for water pressure testing must be
used. Tapered winter plugs will not
hold. Threaded plugs or PVC caps are
another choice.
Evacuate all water from the lines; it
may be weeks or months before fresh
water is run through. Also, pressure
testing when cold temps are creeping in
may pose a problem with freezing.
Backfilling your piping with clean
material prevents damage. We often
use sand to cover pipes at least 8
feet and top off with the spoils from
excavation, removing any rocks as we go. Though the excavated material is
sometimes unsuitable, we will truck
in clean material.
Now that your equipment and
pipe are in place, the next step is to
label your pipes at your equipment
set. Hopefully, you have identified
your pipes as they were set in the
trenches. There are few label makers
on the market that allow for custom
identification. Use labels that are
specific for outdoor applications.
Don’t use a Sharpie! Labeling
equipment allows your customers to
easily identify an equipment problem
in case of a frantic phone call.
Be neat, clean and professional.
Make your equipment sets a thing of
beauty, and you can be proud of what
you’ve accomplished.
Kevin Misley, president of Mystic Pools, has
been involved in the swimming industry since
1983. He started his company in 1986 in the
service sector. Over the years, the company
has incorporated renovations and new
construction.