Aug 1, 2011 12:00 PM, By Charles E Wilson
Minnesota propane distributor upgrades operations
A crop drying system can consume 250 gallons of propane an hour when running on high, according to Greg Pirkl, owner of Pirkl Gas Inc in Owatonna, Minnesota. Even though farms may have five to six large storage tanks, propane distributors and their bobtail drivers have to scramble to make sure farms don't run out of fuel while drying is underway.
“Drying season usually starts around the beginning of October and continues through Thanksgiving, Pirkl says. “The objective of a drying operation is to lower the moisture content of feed corn to 16% maximum. Some of the farms in our area run their drying systems at 23 million Btu, and that takes a lot of propane.
“Currently, we're serving 75 farms with corn drying systems, and they get daily propane deliveries during the drying season. Most of these farms will have two to six 1,000-gallon propane storage tanks, but the largest operations have 18,000- to 30,000-gallon storage tanks that take full propane transport deliveries. We don't run transports, but we arrange the deliveries.”
Pirkl Gas also supplies area farmers raising hogs. “Farmers often have to heat the barns when they have very young hogs,” Pirkl says. “Farmers will keep the barn at around 80°F for about a month. Each hog barn usually has a couple of 1,000-gallon propane tanks.”
Agricultural activities account for about half of the business for Pirkl Gas. Residential customers make up the other half.
“We serve about 100 farms and 1,300 residential customers, and most are within a 35-mile radius of Owatonna,” Pirkl says. “This is a mom-and-pop family business, and we are lifelong members of this community. That is a key to our success.”
The operation that evolved into Pirkl Gas was started in the late 1950s as an Amoco petroleum jobber. Pirkl's father bought the jobbership and the Owatonna bulk plant that was part of it in 1973. The operation distributed branded lubricants and refined fuels.
Pirkl started working for his father in 1978 and bought him out in 1989. At the time, he saw that many of the company's fuel oil customers were moving to propane. In 1995, he bought a small propane distributor in Meriden (seven miles west of Owatonna) that had 275 customers.
Five years later, Pirkl made the decision to focus exclusively on propane. “We saw that many of our fuel oil customers were moving to propane,” he says. “We also felt that we were getting spread too thin with the diverse operation. So, we sold the petroleum jobber side of the business to concentrate on propane.”
Pirkl Gas started with one propane bobtail and a single 18,000-gallon propane storage tank. Petroleum storage tanks were removed from the Owatonna facility and were replaced with propane tanks. Growing conservatively over a 15-year period, propane storage capacity has now reached 210,000 gallons for the two bulk plants — a 30,000-gallon tank in Owatonna in 1996 and another in 2000, three 30,000-gallon tanks in Meriden in 2005, and two 30,000-gallon tanks in Owatonna in 2010.
“Storage capacity is critical in our operation,” Pirkl says. “We get three to four propane transport deliveries a day during the corn drying season, and we get two to three transport loads a day during the winter. Shipments to our bulk plants come from pipeline terminals in Eagle Lake and near Mankato (Minnesota). Shipments also can come from a pipeline terminal in Clear Lake, Iowa. For years, Jensen Transport in Mankato has been handling our bulk shipments, and they take great care of us.”
Pirkl Gas' delivery fleet grew from a single bobtail to six, and product capacity has increased with each new truck purchase. Bobtail capacity now ranges from 3,200 gallons to 5,200 gallons. Smaller trucks are used for residential deliveries, while the larger bobtails are preferred for farm deliveries.
“We've been buying a truck or two a year for the past several years,” Pirkl says. “We don't want the fleet to get too old, because we have to be able to count on the trucks when our customers need propane. This is a competitive business, and we have been able to meet the challenges by steadily upgrading our fleet and bulk plant capabilities.”
The propane distributor has standardized on Freightliner Business Class medium duty chassis for its bobtails. “We bought our first Freightliner in 2002,” Pirkl says. “We hadn't done much equipment replacement before that.”
Pirkl says he chose Freightliner because the local dealer (Westman Freightliner) provides great sales and service support, and Don Neeb, a salesman at the dealership, works closely with Pirkl to spec the best truck for propane deliveries. Without question, the Business Class model is a solidly built truck that performs well in propane delivery service. “It's a dependable truck, and it has great visibility and maneuverability,” he says.
Pirkl also has high praise for Arrow Tank and Engineering Co Inc, the company that fabricates the MC331 cargo tanks and assembles the bobtails. “We bought our first Arrow Tank unit the same year we started with Freightliner,” Pirkl says. “Arrow Tank does a great job for us. We have an excellent salesman in Tim Schweppe.”
The propane distributor has begun a shift from side-mounted pumping cabinets to enclosed rear decks. Decking and cabinets are fabricated from galvanneal steel sheet. Reasons for the switch include more delivery flexibility.
Bobtails are specified with Blackmer's TLGLF3 product pump. Pirkl says he uses Blackmer because pumping capacity meets his needs and the pump offers constant flow rates. The pump can be used with Blackmer's two-inch external bypass valve, which improves reliability and dependability.
On the newest bobtail in the fleet the product pump is powered by a STAC Manufacturing Thermaflow model 500P hydraulic system. The compact hydraulic unit uses propane in the cargo to cool the hydraulic oil, which significantly reduces the amount of oil needed for the unit.
Pirkl Gas also is outfitting its bobtails with a STAC Manufacturing heat exchanger that warms the propane in the cargo tank for faster, smoother pumping. “This heat exchanger is one of the best equipment changes we've made on our trucks,” Pirkl says. “It is very beneficial in the winter, because it helps keep head pressures high.”
Product flow also is improved by the mandrel bends Arrow Tank uses for piping on its bobtails, according to Schweppe. Bobtail hardware also includes RegO manual internal valves, pressure-relief valves, and hose nozzles; Liquid Controls meters and registers; Thermoid product hoses; and Hannay reels.
“We design our bobtails for a long life, and that includes using equipment such as Thermoid's Polar Flex hose, which provides greater cold weather flexibility,” Schweppe says. “We also use larger hose reel motors (two-thirds horsepower).”
Despite the steady increase in storage and propane delivery capacity, Pirkl Gas reached a critical point in 2009. The summer that year was one of the wettest in the Upper Midwest in many years, which meant that the region's corn crop was essentially waterlogged when it was harvested. Pirkl Gas was stretched to the breaking point trying to keep up with demand for the propane needed to dry the corn.
“We had our best year ever in 2009, but it took forever to load our trucks at the Owatonna bulk plant,” Pirkl says. “At the time, we had just a single pump at the plant. “We decided that we had to add more storage and provide faster loading capabilities.”
It was clear that the Owatonna bulk plant needed an upgrade, but increased pumping capacity was just part of it. When the bulk plant was built, the propane storage tanks were placed at ground level despite the fact that the area was prone to flooding.
Another concern was the approaching valve upgrade mandate falling under the National Fire Protection Association's (NFPA's) Section 58 guideline. This safety requirement took effect July 1 and requires all bulk storage tanks with a volume of more than 4,000 gallons water capacity to be fitted with internal valves or an emergency shutoff valve that is located near the tank inlet or outlet, according to Bill Holmes, regional director, United States and Canada, for Pump Solutions Group, which includes Blackmer, Wilden, Griswold, Neptune, Almatec, and Mouvex.
Put simply, NFPA Section 58 brings dramatic changes to the equipment that can be legally used in propane distribution and storage systems, according to Holmes. Since there are no exceptions to the Section 58 rule, and no classes of “grandfather” exemptions were created, operators of propane storage facilities that fall under the purview of the new requirement had to get their tanks into compliance by the July deadline.
Bulk plant upgrade
In light of all these factors, Pirkl decided this was a good time for a major overhaul of the Owatonna bulk plant. He turned to LPG & NH3 Supply Inc for design and installation of the equipment that would help modernize the Owatonna bulk plant. LPG & NH3 was a supplier of equipment to Pirkl Gas for several years and had played a role in building the propane distributor's Meriden bulk plant, making it an obvious partner for the Owatonna plant expansion.
Due to the flooding risk, the first order of business was raising the two existing storage off the ground and placing them on piers about five feet above grade. Two additional storage tanks were then installed, also on piers. Raising the storage tanks couldn't have been more timely.
“Ironically, the summer of 2010 brought torrential rains that flooded the whole area around the Owatonna bulk plant,” says Jeff Munzel, vice-president of LPG & NH3 Supply. “Because the tanks are now set so high and the pumps are abnormally high off the ground, the upgrade saved the plant, basically.”
Also as part of the upgrade: two product pumps were installed at the north end and connected by manifold to all four storage tanks, allowing the operator to load with one or two hoses at once. Another pump was installed at the opposite end and manifolded to all four tanks for even more loading capacity.
Together, the three pumps have the ability to pump 525 gallons per minute, which has reduced overall loading times from 40 minutes down to 13 minutes for a 5,000-gallon bobtail. This also means that Pirkl Gas can now turn the storage tank inventory three times faster than it could in the past, increasing the amount of propane it can sell in a shorter period of time. Pirkl Gas is now able to save roughly nine hours of loading time per truck per month, essentially giving the company an extra day of delivery time for each bobtail.
To ensure maximum loading efficiency at the bulk plant, Pirkl Gas chose Blackmer three-inch LGL sliding vane pumps. “The Blackmer pumps have made a tremendous improvement at our Owatonna bulk plant,” Pirkl says. “They are highly reliable, very quiet, and have improved our load times dramatically due to their efficiency.”
These product pumps can handle all that the propane distributor throws at them because they have been designed for maximum performance and reliability under the most severe operating conditions. Standout features include cavitation suppression liners that reduce noise, vibration, and wear; replaceable casing liners and end discs; ductile-iron construction with internal relief valves; self- priming and dry-run capabilities; and vanes that can be replaced with removing the pump from the piping system.
The improvements have given the second-generation propane distributor an up-to-date bulk plant that can operate fast, efficiently, and cost effectively. Pirkl Gas is now one of the most competitive propane suppliers in the region.
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