This is excerpted for brevity. The entire NICOR report is available from Ionix.

Nicor Technologies Project : NTI-8301
Field evaluation of the Ionix Static Suppression Cartridges

Project Manager: Hitesh Patadia
Principal Investigator: Paresh Purohit

The field test is devised to take place in two separate phases. The first phase involved installing the Ionix unit on a plastic distribution systems supplied be a single regulator station to determine whether the filter would be able to eliminate the static buildup on the inside of the pipe. The second phase will allow co-mixing to occur, by allowing one regulator station to supply treated gas, while the second regulator station will supply untreated gas. For both test, a 6” nozzle Ionix filter will be used. The specific unit is capable of handling flows up to 950,000 SCFH.

The NICOR Gas distribution systems selected is comprised of 0.5 miles of 1” PE pipe, 10 miles of 2” PE and 4.63 miles of 4” PE. Two system regulator stations, operating at 60 PSI previously fed the system. The secondary regulator station was backed off to an outlet pressure of 45 PSI, in order to ensure a one way feed and that the Ionix membrane treated the entire gas volume entering the distribution system. The filter was installed downstream of the primary regulator station at a point where the distribution system transitioned from steel to PE.

Initial readings were take at four sites selected downstream of the filter installation site. The exact locations of the four test sites, with respect to the filter installation site, are illustrated in Figure 2. The initial readings were taken on the service riser, where the service exits the ground, just before the tie-in to the customer’s riser. The service riser was first thoroughly wiped clean with a rag and a 99% by volume alcohol solution to dissipate any charges that may have been built up on the outside of the service riser. The voltage readings built up on the inside of the pipe were taken using an Anderson Electronics Model DCA 1200 voltmeter.

Natural gas was allowed to flow through the unit for two days to purge the distribution systems of untreated gas, and ensure the gas contained in the system had passed through the Ionix unit. Daily readings were taken at each of the four test sites for a period of two weeks. Thereafter, monitoring continued on a weekly basis for a period of 60 days.

DESCRIPTION OF UNIT INSTALLATION

The 6” nozzle size Ionix unit (SGFTJR6) was initially assembled at Nicor Gas’ Crystal Lake facility. Once the assembly was completed and pressure tested for leaks, the prefabricated unit assembly was taken out to the installation site. At the time of installation, two stops were dropped on either side of the existing 4” PE distribution pipe and the existing section of PE main was removed. Next, the unit assembly was electro-fused in the place of the old pipe. After allowing sufficient time for cooling, the bypass valve was opened and the gas allowed to flow through the new pipe, bypassing the Ionix unit. At this point, the Ionix filter membrane was placed within the casing after which the inlet and outlet valves were opened and bypass closed, to initiate gas flow through the Ionix Anti Static unit.

Results of the tests are listed in Table 1 below. The initial readings, taken on May 27 1998 indicate a static voltage reading of -500V, -400V, -300V and -300V, respectively at each of the four test sites. As shown in Chart 1, the static electricity was dissipated within 4 days of the Ionix filter installation. The time frame in which the charges were dissipated was anticipated due in part to relatively low flow rates through the distribution system of approximately 20,000 SCFH during the summer months.

The installation of the Ionix Anti Static filter reduced the resistivity of the gas flowing through the unit, effectively preventing static buildup on the inside of the PE pipe wall. This reduction in static buildup may reduce the chance of pin holing and arc-induced ignition at excavation sites and during repair of hit PE mains, thus reducing the potential of unintended natural gas ignition, risk to personnel working on side and potential property damage.

Location map of test area            Hydraulic schematic of test area

Daily readings taken at test sites

Initial reading:

Date Site 1 Rdg (V) Site 2 Rdg (V) Site 3 Rdg (V) Site 4 Rgd (V)
5/27/98 -500 -400 -300 -300

Daily readings:

Date Site 1 Rdg (V) Site 2 Rdg (V) Site 3 Rdg (V) Site 4 Rgd (V)
6/04/98 -400 -100 -300 -400
6/05/98 -400 -200 -100 -100
6/08/98 0 0 0 0
6/09/98 0 0 0 0
6/10/98* -200 -100 -100 -100
6/11/98* -100 -100 -100 -100
6/12/98 0 0 0 0
6/15/98 0 0 0 0
6/16/98 0 0 0 0
6/17/98 0 0 0 0
6/18/98 0 0 0 0
6/19/98 0 0 0 0
6/22/98 0 0 0 0
6/29/98 0 0 0 0
7/07/98 0 0 0 0
7/10/98 0 0 0 0
7/20/98 0 0 0 0
7/27/98 0 0 0 0
8/04/98 0 0 0 0

* This static buildup may have been the result of one of two factors: 

  1. The service risers could not be completely dried due to rain or, 
  2. The secondary regulator station, previously backed off to a pressure of 45 PSI, and may have kicked on due to the upstream pressures dropping below 45psi.

Daily readings taken at test sites AFTER IONIX REMOVED FROM GAS LINE

Daily readings:

Date Site 1 Rdg (V) Site 2 Rdg (V) Site 3 Rdg (V) Site 4 Rgd (V)
10/09/98 -100 -200 -100 -100
10/12/98 -100  -100 -300 -200
10/13/98 -100 -300 -300 -200
10/14/98 -200 -100 -100 -100
10/15/98 -100 -400 -100 -200
10/16/98 -300 -400 -400 -300
10/19/98 -200 -300 -400 -400
10/20/98 -100 -200 -300 -300
10/21/98 -400 -400 -200 -400
10/22/98 -300 -400 -400 -400
10/23/98 -300 -300 -400 -400
10/29/98 -400 -400 -200 -300
11/06/98 -300 -300 -400 -400
11/16/98 -200 -300 -400 -400
11/20/98 -200 -400 -300 -400
11/25/98 -300 -300 -400 -400

CONCLUSION

The Ionix Static Eliminator effectively eliminated any existing static on the PE distribution system. It is also worth noting that, installed on a single-feed distribution system, the Ionix Static filter membrane also prevented any future buildup of static electricity on the existing PE distribution system.

However, when the Ionix Static Eliminator is installed downstream of only one of the multiple regulator stations that are supplying gas to the distribution systems, the static again increased to levels observed at the beginning of the test.