Air Channel Testing PVC
Geomembrane Thermal Welds

Years of R&D by EPI have resulted in a NEW Testing Method for PVC geomembranes...  In June 2005 a new Air Channel Testing Specification was adopted by ASTM
ASTM D7177-05 Standard Specification for Air Channel Evaluation of
Polyvinyl Chloride (PVC) Dual Track Seamed Geomembranes. 

EPI first began Dual Track Thermal Welding of PVC field seams in 1992.  After years of experimenting, field trials, and equipment modifications & improvements, EPI can now provide the highest quality thermally welded PVC field seams available anywhere.

Using a hot air  welder with a dual track nozzle, EPI's installation crew can weld seams leaving an air channel   between the welds. EPI has the expertise to complete air channel testing of dual track thermal welded PVC field seams. Testing is accomplished by sealing both ends of the seam and introducing air pressure into the channel between the two parallel welds. The seam is pressurized to the minimum required pressure to verify the minimum of 15 lb/in peel strength, based on the ambient sheet temperature of the PVC geomembrane material.  The pressure is monitored to insure weld integrity throughout the seam.  The minimum pressure is determined according to the chart shown below.

Ø Click for Slideshow

Air channel testing a dual track weld is an improved non-destructive testing method for field seams over air lance testing a single weld. Air channel testing will find flaws and weak areas that would otherwise be missed by an air lance. Air channel testing was developed to replace air lance testing and has proven to be a superior non-destructive test for PVC field seams.

Pressure used in each test varies with the temperature of the PVC geomembrane.  Air channel testing is performed according to EPI QC Standards based on research done by EPI, TRI/Environmental and the PVC Geomembrane Institute.

Click to download Air Channel Testing Video

The chart below lists the required test pressures for air channel continuity and peel strength testing for PVC geomembranes at various sheet temperatures...

Pressure Required to Verify 15 lb/in Seam Peel Strength for PVC
per ASTM D7177

Sheet Temperature ºC	Air Pressure KPa	Sheet Temperature ºF	Air Pressure PSI	Hold Time
4.5	345	40	50	30 Seconds
7	324	45	47	30 Seconds
10	310	50	45	30 Seconds
13	290	55	42	30 Seconds
15.5	276	60	40	30 Seconds
18	262	65	38	30 Seconds
21	241	70	35	30 Seconds
24	228	75	33	30 Seconds
26.5	214	80	31	30 Seconds
29.5	193	85	28	30 Seconds
32	179	90	26	30 Seconds
35	165	95	24	30 Seconds
37.5	152	100	22	30 Seconds
40.5	138	105	20	30 Seconds
43.5	131	110	19	30 Seconds
46	117	115	17	30 Seconds
48.5	103	120	15	30 Seconds
51.5	90	125	13	30 Seconds
54.5	83	>130	12	30 Seconds

 

---

Additional Technical Information:

Eliminating costly tests for PVC geomembranes by using new ASTM D7177 air channel test for field seams

Air Channel Test ASTM D7177 Eliminates Water Balance Test of PVC Geomembrane Lined Surface Impoundment

Strength testing of thermal welded PVC geomembrane field seams using non-destructive air channel methods

Index of Thermal Welding Technical Pages

EPI Thermal Welding Page

EPI Thermal Welding Temperature Page

Air Channel Burst Testing of Thermal PVC Seams  
   
Low Temperature Air Channel Testing of PVC...

Checking in with PGI ~ GFR Article

Thermally Bonded PVC Seams "State of the Art"...

Reduction of Tests for PVC Seams - GFR Article

Air Channel Testing Landfill PVC Geomembrane Seams with EPI Crown Vantage Case Study
Adobe Acrobat Reader 7.0 is required to view this file
 

Send to danrohe@geomembrane.com about this web site.     Phone 800-655-4637