A new version of the drain-cover standard, ANSI/APSP-16, is
scheduled to be released later this year. It will address the
issues that spurred the recall, as well as provide more explicit
guidance to the testing laboratories.
However, some members of the writing committee are already looking
toward fine-tuning the standard further after releasing the
rewrite. Specifically, they hope to include language that would
render the body-blocking element more representative of a human,
including the addition of a material that behaves more similarly to
skin under testing conditions.
Yet even while these modifications take place, some believe the
standard’s basic approach is off-track, while others would
like to see a completely different set of adjustments.
The first group contends that by devising more intricate tests and
mandating specific equipment, the standard-writing committee is
adding layers of complexity to a process that, if anything, should
“They’re just clarifying ways to make a complicated
test procedure more clear, but I think it’s really
unnecessary,” says Brooks Hilton, general manager for
Waterway Plastics, a pool and spa products manufacturer in Oxnard,
Hilton and others believe that most safety concerns could be
satisfied if flow ratings were established to maintain a maximum
velocity specified in the standard. As an example, Hilton cites the
1.5-feet-per-second limit in Florida and other areas.
High water velocity is a significant contributor to suction
entrapment since, in a closed, pressurized system, negative
pressure, or suction, grows geometrically as the speed increases
arithmetically. However, velocity is more difficult to establish
than flow. Because of this, the literature provided by drain-cover
manufacturers will state the highest allowable flow, along
with the velocity achieved at that rate. In a hypothetical
example, instructions could indicate that the drain cover is rated
for 100 gallons per minute, which might produce a velocity of 4.5
feet per second.
If, instead, velocity was the guiding variable, the pull-down force
could be made so weak that any potential for entrapment would be
significantly reduced or eliminated.
Hilton, and others, also suspect this approach would aid in keeping
the various parties honest. “You don’t have to do
testing for [velocity],” he says. “You measure the open
area and do a mathematical equation, and that’s how fast the
water will come through it. There’s no testing, no fudging.
[And] you don’t have to get this expensive, hard-to-find,
For this solution to be effective, however, it would have to be
implemented in concert with additional guidance on such issues as
sump dimensions, cover height and geometry, as well as requiring
properly plumbed multiple-suction outlets for each pump.
On the other end of the spectrum are those who believe that more
fine-tuning should be performed for the testing to better reflect
the real world. One expert, for instance, would like to see
additional changes in the body-blocking test. Bill Rowley, a
designer and consultant who has studied entrapment for more than
two decades, objects to the blocking element being pulled off the
drain in one motion. In an actual entrapment, he says, the swimmer
only needs to separate a portion of his or her skin from the cover
to break the seal.
“If you or I got stuck on a drain, we don’t lift
straight up,” says Rowley, president of Rowley International
Inc. in Palos Verdes Estates, Calif., who has performed several
mock entrapments on himself to study the phenomenon. “We
reach out with our arm on one side or other and roll off it.
It’s like peeling off a postage stamp. And the second that
you... have a hole and flow going into it, the vacuum automatically
However, some on the standard-writing committee don’t agree
that a person who’s been trapped, or those frantically trying
to rescue them, would intuitively know this. Instead, they believe,
victims reflexively try to pull off using their whole bodies.
Another detractor wants to see alterations to ratings for the hair
test. His concern involves the so-called “safety
factor” that has been part of the protocol for some time. To
compensate for less-than-accurate readings, laboratories determine
the maximum flow at which a hair entrapment hazard is avoided, then
reduce that number by 25 percent. So if the cover tests safe at 100
gpm, it will be certified for 75 gpm.
Now that a more accurate and duplicable test has been developed,
the standard should remove the safety factor entirely, says Ron
Schroader, a former member of the standard committee and principal
of manufacturer Drainsafe/New Water Solutions in Lake Worth, Fla.
He expects the safety factor will unnecessarily reduce the rating
of several drains.
“They’re going to de-rate the covers so much that
they’re sacrificing a sanitation issue for a safety
issue,” Schroader says. “Instead of being able to turn
over a pool in, say, six hours, like the Department of Health
requires, they’ll only be able to turn it over in maybe 7-1/2
or eight hours.”