| PCRI Product
Evaluation - by Rava Chopra
Smart Parts' Max-Flow Regulator
Over just the past few years, nitrogen/hpa (high pressure air) has become
the propellant of choice in paintball due to the many performance advantages
it offers over CO2. Smart Parts, not a company known for walking away from
a new market, teamed up with Pneu-Ventures some years back to design, build,
and sell a world-beating nitrogen/hpa system. The system they brought to
market was the "Max-Flow." It was reputed to be absolutely the best performing
regulator on the market, its output so consistent that it did not require
secondary regulation to provide exceptionally consistent velocity. Sales
of the Max-Flow suffered, though, due to a high price tag and a reputation
for developing leaks easily.
Just last year, Smart Parts went back to the drawing board to see if they
could address the problems that plagued the original Max-Flow without sacrificing
it's exceptional performance. The result is the 2nd generation Max-Flow currently
available from Smart Parts, also available to owners of the original Max-Flow
as an upgrade.
Design
The Max-Flow is a so-called "balanced" regulator design. That is to say,
the output pressure from the Max-Flow is compared to the set-point and excess
pressure is vented. The advantage of this design is that it provides
exceptionally consistent output pressure without a second stage of regulation
(as will be seen later). As a nice safety bonus of this design, even if the
regulator seat fails completely, the excess pressure is vented off rather
than fed into your 'gun. The ax-Flow regulator has a relatively complex
design when compared to some of the other regulators on the market. To make
your life easier, Smart Parts includes an absolutely wonderful owners manual.
It includes a list of necessary tools. It has step-by-step instructions on
how to set the output pressure, test for problems, troubleshoot, and rebuild
the regulator. It has full regulator schematics listing all of the parts
and seals. They even include recommended output pressures for various paintguns
and filled-bottle weights for CO2 fills! The manual that comes with the Max-Flow
is by far the best that comes with any nitro system (some [Ed note: most]
systems don't come with any manual at all). Looking to the entire paintball
industry, only the Automag's manual is in the same league. Major kudos to
Smart Parts for this.
Smart Parts has done a smashing job eliminating sporadic leaks in the 2nd
generation Max-Flow. With the original Max-Flow, the user would frequently
experience extremely frustrating leaks. In fact, these leaks were caused
by a hard-plastic regulator seat that was easily nicked and did not seal
properly. These leaks past the regulator seat would allow excess pressure
to slowly build in the output. Doing its job perfectly, the regulator would
vent this excess pressure and maintain a perfectly stable output to the paintgun.
While this is a nice example of the advantages of the balanced regulator
design, the leaks were a constant headache. In the 2nd generation Max-Flow,
Smart Parts has replaced this hard plastic reg seat with a differently configured
seat and a much softer seal that doesn't nick and fail like the old seal
did.
Output pressure is set by twisting a large end-cap that screws down over
a large spring that makes up a big part of the regulator's volume. It is
locked in place by cinching a large nut on the same threads up against the
back of the cap. This is one of the system's weak points. This nut does not
do much to deter people from adjusting the pressure after it's been set.
We'd really prefer to see a locking screw to fix it in place for tournaments.
All nitrogen-ready Max-Flow systems come with tank and output pressure gauges,
a standard fill-nipple, and a nitrogen tank. Tanks can be had in three different
sizes: aluminum 53 ci, and fiber-wrapped 68 and 114 ci. The tanks come with
their own on/off pin valves that screw into the Max-Flow system. The on/off
is controlled with a large, easy to turn knob (no wrenches required). As
an added safety measure, the valve has a wide-orifice pin-valve so if the
tank does somehow manage to unscrew from the regulator with the on/off open,
the pin valve will close and prevent the tank from completely venting. In
fact, a channel is cut inside the manifold such that if the tank does start
to back out, the pin valve closes, the o-ring blows out, and the pressure
inside the 'gun is vented, all before the tank becomes completely unscrewed
from the system. Naturally, the tank valve has its own burst disc to protect
from over-pressurization. The valve is also reverse-threaded so it can't
be accidentally screwed into a standard ASA and 3000 psi pumped straight
into your 'gun. It's probably fair to say that the Max-Flow comes with more
safety features than any other system on the market The Max-Flow can be had
as one of two basic setups: 'gun mounted or remote.
The 'gun-mounted system is a bit more compact and comes with the appropriate
parts for bottom-line mounting on most paintguns. The remote system is simpler,
looking a bit like Smart Parts' expansion chamber remotes and including a
steel-braid remote hose and disconnect. The price of the two different systems
is the same.
If there is one thing to complain about with the Max-Flow, it's that it is
big, especially when combined with the bottom-line manifold. Most other nitro
systems on the market are much smaller and more stream-lined than this monster.
It doesn't impair performance at all, but some people are disconcerted by
just how big and goofy it can look.
Design rating [3.5]
Construction:
The Max-Flow system is virtually all aluminum and is designed for 3000 psi
operation only. All of the parts are machined and fit beautifully. All aluminum
parts are anodized black aluminum makes for a much lighter system than some
of the massive stainless steel systems out there.
The 53 ci tank is a thick, heavy aluminum. The 68 ci and 114 ci tanks are
the standard fiber-wrapped tanks that have been in use for years. All nitrogen
tanks for the Max-Flow are rated to 3000 psi. The tank valves are brass
and do not show any signs of significant wear after extended use.
Though there is nothing specifically wrong with the construction of the Max-Flow
system, its 3000 psi limit and fiber-wrapped bottles put it a step behind
the 4500 psi systems and much lighter carbon-fiber wrapped bottles currently
being offered on other nitrogen systems.
Construction rating [3]
Performance:
Most regulators will offer very consistent output pressure as long as the
load (input pressure the regulator has to control) is constant. This is clearly
not the case with nitrogen/HPA systems. With these, you start with a 3000
psi load which drops throughout the game as the tank empties. If you run
the tank completely dry, the regulator could be faced with pressures that
vary from 3000 psi to 0 psi through the game. Clearly, once your tank pressure
drops below the set output pressure, the output pressure will drop with it.
What we are really concerned with is how the output pressure changes as the
tank pressure drops.
To test the Max-Flow, we filled the tank, set the output pressure, hooked
the system up to a paintgun (an Autococker) and fired it 5 times, taking
output pressure measurements after each shot. We then bled 500 psi out of
the tank and repeated the series of 5 readings. We continued to repeat this
procedure until we reached the set output pressure or 500 psi. We ran this
experiment at three different output pressures (200 psi, 500 psi, and 900
psi). For comparison purposes, we ran the experiment in parallel at 500 psi
and 900 psi with Air America's venerable Raptor nitrogen system. The three
graphs included herein show the results of these tests. The error bars are
the standard deviation of five readings taken at any given tank pressure.
These curves represent how consistent the system is from shot-to-shot while
the curve as a whole represents consistency as the tank runs from full to
empty. As you can see, the Max-Flow is remarkably consistent, both shot-to-shot
and over the whole span of tank pressures from completely full all the way
down to the set pressure. Furthermore, this consistency comes at high, medium,
and very low output pressures. There isn't a paintgun out there that this
system will have any difficulty feeding. We am not aware of any other
nitro/hpa system that maintains it's output pressure as impressively as the
Max-Flow
Another issue of course, is flow-rate. We had planned on trying to time the
recharge rate, but found that recharge was represented by little more than
a twitching of our 3" reference test gauge needle. In use, we never experienced
any velocity drop off with rapid fire. Additionally, Smart Parts includes
the Max-Flow as the standard air system for use with their hungry
11-shots-per-second Shocker Turbo. Suffice it to say, the Max-Flow's low-rate
will not be an impediment for most players.
Performance rating [4]
Versatility
The Max-Flow is really more appropriately considered as just the pressure
regulator that comes with regulated Smart Parts gas systems. This is because
the Max-Flow regulator is the only part that is really common to all Smart
Parts systems. It has a single high-pressure input port and four regulated
outputs. These ports are used with a variety of different mounts and fittings
to create bottom-line, remote, nitrogen/HPA, and CO2 based systems. As such,
the Max-Flow is perhaps the single most versatile system on the market. However
you want to run it, Smart Parts can set the Max-Flow up to fit your needs.
Even people who sometimes find themselves shooting nitrogen and other times
shooting CO2 aren't left out in the cold. Smart Parts sells some nitrogen
bottles with standard CO2-tank threads so you can buy your system with standard
threads and screw in the CO2 or nitrogen bottle of your choice. This also
makes it much easier to put CO2 into your Smart Parts nitro bottles (which
are rated to more than sufficiently high pressures to be filled with CO2).
If there is any lack for the Max-Flow, it's in the simple fact that there
aren't many aftermarket bottom-line and drop-forward cradles available for
bottom-line mounting. Any cradle or mount that a standard bottom-line ASA
can be attached to is compatible with the Max-Flow, but you don't see the
same impressive array of aftermarket options as you do for Air America systems.
This is hardly Smart Parts' fault or responsibility, though.
Versatility rating [4]
Price/Warranty
The 2nd generation Max-Flow nitrogen/hpa system varies from $250 to $390
depending on the bottle you want with it. While these prices are a good bit
higher than those of other 3000 psi nitro systems, you do have to keep a
few things in mind. First, the Max-Flow offers more and superior performance,
safety, and convenience features than many other systems. It also offers
such exceptionally consistent output that you may never need a second regulator
(like a Uni-Reg or Stabilizer) to further control the input pressure to your
'gun; a potential savings of over $100 there. As such, the Max-Flow is a
good value, if not the price leader in this segment.
The warranty that Smart Parts offers with the Max-Flow is 1 year from the
date of purchase and covers defects in materials and workmanship.
In general, I've found Smart Parts to offer good, competent customer service.
Price/Warranty rating [3]
Conclusion:
The Max-Flow is a strange mix. It offers perhaps the most impressive combination
of performance, convenience, and safety available in a nitrogen system
today. Missing, though, are such popular, state-of-the-art features as 4500
psi operation and ultra-light carbon fiber tanks. For the performance junkie
who wants the ultimate in output pressure consistency, the Max-Flow is a
dream come true. If Smart Parts would offer it in 4500 psi and could pack
it into a smaller, more elegant package, the Max-Flow would be perfect.
PCRI IS PLEASED TO AWARD THE SMART PARTS 2ND GENERATION MAX-FLOW HIGH
PRESSURE SYSTEM OUR THREE AND ONE-HALF STAR RATING. |
