Slow and Easy

A valve exercising initiative using automated equipment helps a Michigan city correct valve problems and reduce service disruptions
Slow and Easy
Steve Wolff of Wachs Water Services uses the ERV-750 automated valve operator and TDS Recon handheld microprocessor to exercise a valve on a 16-inch water transmission main. The arm extends 13 feet and produces 750 foot-pounds of torque.

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The City of St. Joseph, Mich., had valves on two 16-inch water transmission mains and on 20- and 30-inch transmission mains that had not operated for 35 years.

The city also maintains the Southwest Michigan Water and Sewer Authority distribution systems, serving three townships and two villages. “We had 40 breaks a year throughout the system,” says water plant superintendent Greg Alimenti. “Inoperable valves prevented us from isolating the problems to a city block, so we were always inconveniencing more customers than necessary.”

Customers lost service for two to eight hours per episode. In 2010, the Michigan Department of Environmental Quality conducted an extensive sanitary survey as required by the federal Safe Drinking Water Act and recommended that the city begin a valve-turning program within 12 months or face a citation.

Alimenti had worked with a Wachs Water Services field team when they exercised the valves on the authority’s distribution system the previous year. “I developed an appreciation for their knowledge and was comfortable with them, and they assured us a satisfactory price,” he says.

The following June, Wachs Water Services exercised 1,045 valves in the city without incident and without disrupting service, in the process providing Alimenti with valuable information about the transmission system and required maintenance.

 

Setting the stage

The 16 mgd (design) St. Joseph Water Filtration Plant delivers 12 mgd to a combined population of 33,000. The city maintains 240 miles of ductile iron water pipes installed in the 1930s and 1940s.

The city’s last valve exercising program was in the late 1990s, before diminishing manpower was redirected to installing taps as the authority’s distribution system expanded. “I was concerned about allowing staff to attempt to close the valves, as they lacked experience and could break valves or cause them to stick,” says Alimenti.

Before Steven Wolff, Alex Lowe, and Mark Justice arrived in the operations vehicle outfitted with Intelligent Automation equipment from E.H. Wachs, Alimenti’s team updated the valve atlas, paying special attention to valves near the water plant and booster stations. “We couldn’t close them while the facilities were pumping high volumes of water,” Alimenti says. “It took close communication with Steven and Alex to establish the timing.”

 

Careful turning

The automated machines, designed for one-man operation, enabled the team to split up. Wolff concentrated on the 30-inch transmission main that feeds two-thirds of the distribution system. Using the truck-mounted ERV-750 articulated arm with automated valve turner, he accessed a critical valve near the plant.

After inserting the telescoping keyway, Wolff zeroed out the revolution counter, then controlled the operation using a TDS Recon handheld microprocessor. The torque wedge feature on the valve turner transferred torque to the frame with zero slip, allowing him to apply up to 750 foot-pounds of torque in a graduated sequence of five to 10 revolutions down and two to three up.

Wolff also confirmed Alimenti’s reservations about letting his staff exercise the valves. “I was shocked to hear that a man cranking on a valve can apply 400 or 500 foot-pounds of rotational torque without knowing it, and break the valve or lock it up,” says Alimenti. “Steve went through about 30 sequences before he believed the valve would open again if he closed it. His expertise gave us the confidence to tell him to go ahead.”

Wolff opened and closed the valve until it operated in one smooth continuous motion. His handheld VITALS mobile data logger gathered the valve data and synchronized it with the city’s water management software.

 

What’s down below

Meanwhile, Lowe and Justice concentrated on exercising other utility valves and those on fire hydrants using the Turn-N-Count manual T-wrench with digital counter. The ratchet mechanism on the unit’s telescoping keyway reduced the range of motion necessary to rotate the tool. Turning the directional lever reversed rotation.

The work took a month. All the data was reviewed by information management analysts at Wachs Water Services before Alimenti received the report. The results surprised him.

Wolff and Lowe found 383 undocumented valves, 16 valves fully closed and 13 partially closed on 6-inch lines, along with four hydrant valves fully closed and 10 partially closed. “Partially closed can be anything from 5 percent to 92 percent,” says Alimenti. “That’s really important because we try to loop water mains to improve pressure, and partially closed valves defeat the purpose.”

The report also generated 104 work orders that included covered and frozen valves, valves that needed raising, free-spinning valves, and stuck or missing lids. “We now have a valuable tool that is enabling us to get a handle on our system,” says Alimenti. “Another great value is knowing that the critical main transmission valves will close in an emergency. That helps me sleep a lot better.”



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