Page 19 - Oil and Energy January 2013

by customer complaints. At velocities lower
than 2 feet per second, dissolved oxygen
will tend to come out of solution and cause
air problems within the system.
To determine the head loss of a zone,
start by measuring the total length of the
zone, including the element. In this case
we have 80 feet of ¾” pipe connected to
the 50 feet of element for a total of 120
feet. Now multiply the total by 1.5 to allow
for fittings, valves, etc. Fittings and valves
produce pressure drop in a system that is
the equivalent of a few feet of pipe each, so
multiplying by 1.5 accounts for most basic
fittings and valves.
If you have high head items in your
system like flow checks or 3-way valves,
you will have to add some more head later.
You now have the total developed equiva-
lent length of the circuit and you multiply
that by .04. This number represents 4 feet of
head per 100 feet of copper pipe. That head
number applies as long as the pipe has been
sized according to the velocity guidelines
shown in the previous paragraph. The end
product is the head loss for the zone. 120 x
1.5 x .04 = 7.2 feet of head. We must now
find a circulator that will deliver 3 gallons
per minute against 7.2 feet of head.
CHECK THE CHART
If we take a look at the Taco “00” series
performance curve chart, we can determine
Taco “00” Series Performance Curve Chart
which circulator we should use for this
zone. As long as the point at which the
system operates is inside of or on the line
that the pump operates, you are assured
that the pump will deliver heat at the right
temperature to the zone. If that point falls
outside the pump curve, your pump will
not be able to deliver the maximum amount
of BTUs needed under design conditions.
Simply put, in the coldest weather, the
system can’t reach the required comfort
level. In the case of an indirect water heater
it will be slow in recovery.
First, on the bottom axis, we find the
flow rate – in this example, it is 3 gallons
per minute. On the vertical axis we have
head loss – in this example it is 7.2 feet of
head. We follow the two lines until they
intersect to find our system operating point
of 3 GPM at 7.2 feet of head. Next, we look
at the performance curves to find out which
circulator would make the best selection.
In this example, a 006, 005 or a 007 would
be good choices – with the most likely
choice being the 007, since it’s the most
common and most readily available.
Once you understand the dynamics
that are going on in a system, you can size
and select the right circulator for the job.
In a later article we will discuss the effect of
pump speed on system performance, where
multi-speed and variable speed pumps are
used and how they function.
Industry News
API SUES EPA OVER
2013 BIODIESEL MANDATE
The American Petroleum Institute
(API) filed a lawsuit in the U.S. Court
of Appeals for the District of Columbia
recently against the U.S. Environmental
Protection Agency (EPA) for its deci-
sion to mandate the use of 1.28 billion
gallons of biodiesel in 2013, a 28 percent
increase from the 2012 requirement. API
also filed a petition for administrative
reconsideration of the 2013 biodiesel
mandate with EPA.
“EPA’s overzealous 2013 biodiesel
mandate is unworkable, could raise the
costs of making diesel fuel, and should
be reduced,” said Bob Greco, API group
downstream director. “In its final rule,
EPA admitted the costs of increasing the
biodiesel volume requirement for 2013
outweighed the benefits by as much as
$425 million. Furthermore, fraudulent
biofuel credits that have plagued the
system since last year and have yet to be
resolved could inhibit industry’s ability to
meet EPA’s higher biodiesel mandate.”
EPA has uncovered more than 140
million invalid renewable fuel credits,
known as RINs, generated by three biod-
iesel companies, representing between
5 and 12 percent of the biodiesel market.
“The fraudulent RIN problem is
having, and will continue to have,
significant impacts on the biodiesel
marketplace that make it more difficult
for companies to comply with EPA’s
mandate,” Greco said.
IMPORTS OF CANADIAN CRUDE INCREASE
U.S. imports of
Canadian crude oil rose
to record levels during
the first eight months
of 2012, with Canada
accounting for a growing
share of total gross U.S.
imports, according to the
U.S. Energy Information Administration
(EIA). The United States is importing
more crude oil fromCanada, even though
the total amount of crude oil America
buys from foreign suppliers is falling.
Canada is the largest supplier of
foreign oil to the United States, followed
by Saudi Arabia, Mexico, and Venezuela.
Almost 99% of Canadian oil exports
are sent to the U.S. market. Canada
accounted for approximately 25% of U.S.
crude oil imports in 2011, averaging 2.2
million barrels per day.
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