33 05 05.41 - Air Testing.pdf

33 05 05.41 - AIR TESTING

1.0 General

1.1 Summary

A. Section Includes: Low-pressure air testing of gravity sewer piping.

B. Related Requirements:

1. Section 33 31 11 – Public Sanitary Sewerage Gravity Piping: Pipe materials, manholes, and accessories normally encountered with gravity sewerage piping.

1.2 Submittals

A. Section 01 33 00 – Submittal Procedures: Requirements for submittals.

B. Submit following items prior to start of testing:

1. Testing procedures.

2. List of test equipment.

3. Testing sequence schedule.

4. Provisions for disposal of flushing and test water.

5. Certification of test gage calibration.

C. Test and Evaluation Reports: The Contractor shall indicate results of piping tests.

D. Qualifications Statement:

1. Submit qualifications for applicator.

2.0 Products

2.1 Air Testing

A. Equipment: The Contractor shall provide a complete air testing system specifically designed and constructed for internal air pressure tightness integrity testing of sewer piping joints. The equipment shall be constructed in such a way as to provide means for introducing air, under pressure, into the void area created by the expanded ends of the joint-testing packer and a means for continuously measuring the actual static pressure of the air within the void area only. The system shall include, but not be limited to, the following items and features:

1. Packer: Open end, cylindrical casing of a size less than the pipe diameter, remote controlled for forward and backward movement within the sewer mains:

1. Air-inflatable sleeves (or diaphragms) mounted at each end of the casing exterior with the ends of sleeves fastened to the casing. Devices that have sleeves which may require extreme pressures to “seat” against the inside periphery of the sewer main pipe are not permitted.

2. Regulate expansion of air-inflatable sleeves by precise pressure gauges and controls. Under no conditions will hydraulically or mechanically expanded devices be allowed.

3. Pass conduits leading from the surface though one end of the packer casing adapted to supply air, under pressure, to the space at the center of the casing.

2. Compressed Air System: Compressed air system shall include compressed air source, piping, valves and pressure gauges to control the rate of air flow to the packer sleeves and test section:

1. To prevent loading the test section with the full pressure of the compressor, the test equipment shall be provided with an approved pressure regulating device.

2. Pressure gauges shall be calibrated to 0.1 psi.

3. Test Monitoring Equipment: Provide test monitoring equipment to transmit the value of the void air pressure to a remote test pressure monitoring gauge or readout:

a. Test pressure monitoring gauge or readout shall be located to allow for simultaneous and continuous observation of the television monitor and test monitoring equipment by the Engineer.

3.0 Execution

3.1 Examination

A. Section 01 73 00 – Execution Requirements: Requirements for installation examination.

B. The Contractor shall verify that piping is ready for testing.

C. The Contractor shall verify that trenches are backfilled.

3.2 Installation

A. Section 01 73 00 – Execution Requirements: Requirements for preparation.

B. Plugs:

1. Plug outlets, wye branches, and laterals.

2. Brace plus to resist test pressures.

3.3 Field Quality Control

A. 01 40 00 – Quality Requirements: Requirements for inspecting and testing.

B. General Requirements: The Contractor shall conduct tests specified herein so that each pipeline installed in the Project is tested to the Engineer's satisfaction:

1. Provide tools, materials, apparatuses, and instruments necessary for pipeline testing.

2. Conduct tests in the presence of and to the satisfaction of the Engineer.

C. Cleaning Prior to Tests: Before tests are conducted, the Contractor shall clean piping including sewers, branches and service connections until free of dirt or silt or construction debris

D. Line Acceptance Test for Gravity Lines: (Leakage tests): After a section of sewer is constructed between adjacent manholes, backfilled and successfully cleaned and passes an alignment test, the Contractor shall perform a low-pressure air Line

Acceptance Test in accordance with ASTM F 1417 and the following:

1. Seal and brace sewer piping at upstream and downstream manholes and at all laterals. Test plug seal before actual use by testing plugs outside the trench in one length of pipe pressurized to maximum anticipated testing pressure. Plugs shall hold without bracing and show no movement. After plug is placed in pipe and sealed, brace or protect as insurance against blow out. Protect workers from potential plug blow out.

2. Introduce low pressure air slowly into sealed sewer section. The test shall be performed as follows:

a. Introduce air pressure slowly to approximately four (4) psig.

b. Determine ground water elevation above spring line of piping.

c. For every foot of ground water above spring line of piping, increase starting air test pressure by 0.43 psi.

d. Do not increase pressure above 10 psig.

e. Allow pressure to stabilize for at least five minutes. Add air only to maintain required test pressure.

f. After the stabilization period, adjust the test pressure to the required test pressure, and disconnect the air supply. Then measure drop in pressure during testing period

g. Minimum Testing Duration in Minutes Per 100 Feet (do not make allowance for laterals):

i. Pipe Size 4 Inches: 3:46

ii. Pipe Size 6 Inches: 5:40.

iii. Pipe Size 8 Inches: 7:34.

iv. Pipe Size 10 Inches: 9:26.

v. Pipe Size 12 Inches: 11:20.

vi. Pipe Size 15 Inches: 14:10.

vii. Pipe Size 18 Inches: 17:00.

viii. Pipe Size 21 Inches: 19:50.

ix. Pipe Size 24 Inches: 22:47.

x. Pipe Size 27 Inches: 28:51.

xi. Pipe Size 30 Inches: 35:37.

xii. Pipe Size 36 Inches: 51:17.

xiii. Pipe Size 42 Inches: 69:48.

h. If air pressure drops more than 1.0 psi during testing period, piping has failed.

i. If 1.0 psi air pressure drop has not occurred during testing period, piping is acceptable; discontinue testing.

j. If piping fails, test reach of piping in incremental stages until leaks are isolated, repair leaks, and retest entire reach between manholes.

k. If unsatisfactory testing results are achieved, make necessary repairs and retest until result meets criteria.

3. Repair visible leaks regardless of quantity of leakage.

4. After laterals are installed, re-test line in accordance with the above procedure if line is initially tested before the installation of laterals.

5. Where lines are live and carry flow, perform Joint Acceptance Test by testing one joint at a time as described in paragraph 3.3.C, below.

E. Joint Acceptance Test for Gravity Lines (Leakage Tests):

1. Joint Testing Equipment Control Test: A two-part control test shall be performed by the Contractor to ensure the accuracy, integrity, and performance capabilities of the testing equipment; testing as follows:

a. Demonstration Test: Prior to starting the air testing work, perform a demonstration test in the presence of the Engineer using a test cylinder, furnished by the Contractor, constructed so that a leak can be simulated. The demonstration test shall use the procedures specified in this Section.

i. The purpose of the demonstration test is to establish that the air testing system is capable of meeting the specified test criteria.

ii. If this test cannot be performed successfully, the Contractor shall repair or otherwise modify his equipment and repeat the test until the results are satisfactory to the Engineer.

iii. The Engineer may require that this test be repeated at any time during the joint testing work when, in the Engineer’s opinion, the testing results are suspect.

b. Readiness Test: Prior to commencing joint testing in each section of sewer main piping, perform a readiness test in the presence of the Engineer. Position the air testing packer on a section of sound sewer pipe between pipe joints and perform a test as specified.

i. The purpose of the test is to check that the piping is properly cleaned for air testing and the air testing equipment system is operating in accordance with the requirements of the Specifications.

ii. If this test cannot be performed successfully, the Contractor shall remove the air testing packer from the sewer section and repair or otherwise modify his equipment and repeat the test until the results are satisfactory to the

Engineer.

2. The air testing packer end elements shall be expanded so as to isolate the joint from the remainder of the line and create a void area between the packer end elements and the pipe joint. The ends of the testing device shall be expanded against the pipe with sufficient inflation pressure to contain the air within the void without leakage past the expanded ends.

3. Contractor shall then introduce pressurized air into the isolated void created by the testing device. Pressure shall be applied until it is determined that the pressure cannot be built in the void or four (4) psi as recorded by the void pressure monitor.

When either of these conditions is reached, Contractor shall shut off the air supply.

4. If the required pressure cannot be developed, joint shall have failed the test. If the required test pressure in the void was increased to four (4) psi, rate of decay of this pressure shall not exceed one (1) psi in 15 seconds. The joint being tested will also have failed if the pressure drops more than one (1) psi in 15 seconds. The line shall then be repaired prior to the retest.

5. Test Records:

a. During joint acceptance testing, records shall be kept by the Contractor which include identification of the sewer section tested, test pressure used, location

(footage) of each joint tested, a statement indicating test results (passed or failed) for each joint tested, test pressure achieved and maintained for each joint passing air test, weekly equipment pressure test results, sewer section barrel test results, and air temperature at time of testing joints.

F. Construction Testing – Lateral Connections:

1. To determine if a lateral connection passes the air test, the packer and sealing bladder shall be inflated to isolate the area around the connection and the first joint of the lateral pipe.

2. Contractor shall then introduce an air pressure of four (4) psi into the isolated void and shut off the air supply. Contractor shall then measure and record the length of time for the pressure to drop from four (4) psi to three (3) psi.

3. The joint test for the lateral would consider to be passed if the time delay for the pressure drop exceeds 15 seconds.

G. Time for Making Test:

1. Engineer shall be present during the operating of valves required to fill mains for leakage test.

2. Contractor shall advise Engineer of any test at least 48 hours in advance. No testing will be authorized unless ambient air temperature is 35◦ F or higher.

3. All tests shall be witnessed by Engineer.

4. Contractor shall furnish laboratory calibrated test gauges and measuring devices for the leakage test.

H. Acceptance: Observation of successful testing of this Section by the Engineer does not constitute acceptance of the system or any portion thereof. Upon completion of any determined portion of a total system, and successful testing thereof, the Engineer may recommend final acceptance to the Owner. Only upon final inspection by the Owner or Engineer, and upon written acceptance for same, will the system or portion thereof be considered substantially completed. Upon such acceptance, the warranty period as specified for the manholes and sewers will commence.

1. If, during this final inspection, any irregularities are observed, the condition must be corrected at the Contractor's expense prior to acceptance.

END OF SECTION