Graco ProMix PD2K Installation Manual page 19

Additional Considerations Considerations for
Additional Additional Considerations
Step 1: 1: 1: Determine Determine hardware hardware requirements
Step Step Determine hardware
• Number of pumps (3–4 maximum)
– A Pump (1 or 2)
– B Pump (1 or 2)
– C Pump (1 or 2)
• Pump size (35 cc or 70 cc)
– The third component material ratio determines
the pump size. Ratios less than 1 use a 35 cc
pump, and ratios greater than 1 use a 70 cc
pump.
• Materials plumbed to each pump (resin, catalyst,
thinner, or color)
– Pump #1 (A, B, or C material) — Typically for the
resin material and the highest ratio volume.
– Pump #2 (A, B, or C material) — Typically for the
catalyst material and a lower ratio volume.
– Pump #3 (A. B, or C material) — Typically for a
thinner (solvent, water, activator, or promoter)
and a wide variation in ratio volume.
– Pump #4 — Typically for a dedicated color or a
fourth component.
• Number of colors/materials on each pump
– Number of A Pump color/material valves
– Number of B Pump color/material valves
– Number of C Pump color/material valves
– Number of Pump #4 colors, if used
Step Step 2: 2: 2: Determine Step Determine mix Determine mix manifold mix
• Mix-at-Wall 3K manifolds (manual or automatic
system)
– All three materials are combined at the same 3K
Mix-at-Wall manifold.
• 2K manifolds; combining A and B (or A and C) first,
then A+B to C (or A+C to B) prior to the spray gun.
Some materials can be combined without a pot life,
so only the material from the second manifold may
need to be flushed. (Manual applications can use
Mix-at-Belt and Mix-at-Wall. Automatic applications
can use staged, 2K Mix-at-Wall manifolds.)
– A and B materials combined first, and then C
added (waterborne materials).
332458M
for PD3K+ PD3K+ Systems Systems
for PD3K+ Systems
requirements
requirements
manifold configurations manifold configurations configurations
– A and C materials combined first, and then B
added (solvent reduction for resin for viscosity
control).
– Mix manifold locations are based on material
chemistry, pot life, component viscosities, and
material flush/waste considerations.
Step 3: 3: 3: Determine Step Step Determine location Determine location location of of of PD3K
around the the spray spray booth booth
around around the spray booth
• Includes the proportioner, color stacks, and mix
manifolds.
• Consider plumbing routing, and then determine the
lengths of hosing needed to complete each section
of the plumbing installation.
Step 4: 4: 4: Calculate Calculate line line sizes sizes
Step Step Calculate line sizes
• Determine the individual component flow rates by
spray gun flow and fluid mix ratios.
• Calculate the pressure loss to the first stage
manifold for each component. Select line sizes to
keep component pressure losses as close to each
other as possible.
– Pressure loss = (Constant x Viscosity x Flowrate
x Distance)/ID^ 4
– Constant = 0.000273
– Viscosity = CPS
– Flowrate = GPM
– Distance = feet
– ID 4 = Inside diameter of the hose to the 4th
power
• Estimate the viscosity of material from the first
stage by considering individual material viscosities
and component ratios.
• Calculate the pressure losses for fluid lines to the
second stage manifold. Include the line loss of the
first hose, plus the mixer and hose loss between
the first and second manifold.
• Calculate the final mixed material line loss from the
second manifold to the spray gun.
Optimum line sizing lowers the overall spray
pressures and minimizes significant transitional
effects of flowrate changes.
Configure Your System
PD3K equipment PD3K equipment equipment
19