ASTM E1067-96
(Practice)Standard Practice for Acoustic Emission Examination of Fiberglass Reinforced Plastic Resin (FRP) Tanks/Vessels
Standard Practice for Acoustic Emission Examination of Fiberglass Reinforced Plastic Resin (FRP) Tanks/Vessels
SCOPE
1.1 This practice covers acoustic emission (AE) examination or monitoring of fiberglass-reinforced plastic (FRP) tanks-vessels (equipment) under pressure or vacuum to determine structural integrity.
1.2 This practice is limited to tanks-vessels designed to operate at an internal pressure no greater than 0.44 MPa absolute (65 psia) above the static pressure due to the internal contents. It is also applicable for tanks-vessels designed for vacuum service with differential pressure levels between 0 and 0.06 MPa (0 and 9 psi).
1.3 This practice is limited to tanks-vessels with glass contents greater than 15% by weight.
1.4 This practice applies to examinations of new and in-service equipment.
1.5 The values stated in SI units are to be regarded as standard. The inch-pound units in parentheses may be approximate.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use . (For more specific safety precautionary information see 8.1.)
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: E 1067 – 96 An American National Standard
Standard Practice for
Acoustic Emission Examination of Fiberglass Reinforced
Plastic Resin (FRP) Tanks/Vessels
This standard is issued under the fixed designation E 1067; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope Testing Personnel Qualification and Certification
ANSI/ASNT CP-189 Standard for Qualification and Certi-
1.1 This practice covers acoustic emission (AE) examina-
fication of Nondestructive Testing Personnel
tion or monitoring of fiberglass-reinforced plastic (FRP) tanks-
2.3 Military Standard:
vessels (equipment) under pressure or vacuum to determine
MIL-STD-410 Nondestructive Testing Personnel Qualifica-
structural integrity.
tion and Certification
1.2 This practice is limited to tanks-vessels designed to
operate at an internal pressure no greater than 0.44 MPa
3. Terminology
absolute (65 psia) above the static pressure due to the internal
3.1 Complete definitions of terms related to plastics and
contents. It is also applicable for tanks-vessels designed for
acoustic emission will be found in Terminology D 883 and
vacuum service with differential pressure levels between 0 and
E 1316.
0.06 MPa (0 and 9 psi).
3.2 Definitions of Terms Specific to This Standard:
1.3 This practice is limited to tanks-vessels with glass
3.2.1 count value N —an evaluation criterion based on the
c
contents greater than 15 % by weight.
total number of AE counts. (See A2.4 of Annex A2.)
1.4 This practice applies to examinations of new and in-
3.2.2 FRP—fiberglass reinforced plastic, a glass-fiber poly-
service equipment.
mer composite with certain mechanical properties superior to
1.5 The values stated in SI units are to be regarded as
those of the base resin.
standard. The inch-pound units in parentheses may be approxi-
3.2.3 high-amplitude threshold—a threshold for large am-
mate.
plitude AE events. (See A2.3 of Annex A2.)
1.6 This standard does not purport to address all of the
3.2.4 low-amplitude threshold—the threshold above which
safety concerns, if any, associated with its use. It is the
AE counts (N) are measured. (See A2.2 of Annex A2.)
responsibility of the user of this standard to establish appro-
3.2.5 operating pressure—the pressure at the top of a vessel
priate safety and health practices and determine the applica-
at which it normally operates. It shall not exceed the design
bility of regulatory limitations prior to use. (For more specific
pressure and it is usually kept at a suitable level below the
safety precautionary information see 8.1.)
setting of the pressure-relieving devices to prevent their
2. Referenced Documents frequent opening.
3.2.6 pressure, design—the pressure used in design to
2.1 ASTM Standards:
determine the required minimum thicknesses and minimum
D 883 Terminology Relating to Plastics
mechanical properties.
E 543 Practice for Evaluating Agencies that Perform Non-
3 3.2.7 processor—a circuit that analyzes AE waveforms.
destructive Testing
(See Section 7 and A1.8.)
E 650 Guide for Mounting Piezoelectric Acoustic Emission
3 3.2.8 summing amplifier (summer, mixer)—an operational
Sensors
amplifier that produces an output signal equal to a weighted
E 750 Practice for Characterizing Acoustic Emission Instru-
3 sum of the input signals.
mentation
3.2.9 zone—the area surrounding a sensor from which AE
E 1316 Terminology for Nondestructive Examinations
can be detected by that sensor.
2.2 ANSI/ASNT Standards:
SNT-TC-1A Recommended Practice for Nondestructive
4. Summary of Practice
4.1 This practice consists of subjecting equipment to in-
This practice is under the jurisdiction of ASTM Committee E-7 on Nonde- creasing pressure or vacuum while monitoring with sensors
structive Testing and is the direct responsibility of Subcommittee E07.04 on
Acoustic Emission.
Current edition approved July 10, 1996. Published September 1996. Originally Available from American Society for Nondestructive Testing, 1711 Arlingate
e1
published as E 1067 – 85. Last previous edition E 1067 – 89 (1991) . Plaza, P.O. Box 28518, Columbus, OH 43228-0518.
2 5
Annual Book of ASTM Standards, Vol 08.01. Available from Standardization Documents Order Desk, Bldg. 4, Section D,
Annual Book of ASTM Standards, Vol 03.03. 700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
E 1067
that are sensitive to acoustic emission (transient stress waves) and AE hits above the low-amplitude threshold, AE hits above
caused by growing flaws. The instrumentation and techniques the high-amplitude threshold within specific frequency ranges,
for sensing and analyzing AE data are described. and having sufficient channels to localize AE sources in real
4.2 This practice provides guidelines to determine the loca- time. It may incorporate (as an option) peak-amplitude detec-
tion and severity of structural flaws in FRP equipment. tion for each input channel or for groups of channels. Hit
4.3 This practice provides guidelines for AE examination of detection is required for each channel. An AE hit amplitude
FRP equipment within the pressure range stated in 1.2. measurement is recommended for sensitivity verification (see
Maximum test pressure (or vacuum) for an FRP vessel will be Annex A2). Amplitude distributions are recommended for flaw
determined upon agreement among user, manufacturer, or test characterization. It is preferred that AE instrumentation acquire
agency, or a combination thereof. Pressure vessels having an and record count, hit, and amplitude information on a per
internal operating pressure exceeding 0.2 MPa absolute (30 channel basis. The AE instrumentation is further described in
psia), will normally be tested to 1.5 3 operating pressure. Annex A1.
Atmospheric storage vessels will normally be tested under 7.3 Capability for measuring parameters such as time and
maximum operating conditions. Pressure vessels having an pressure shall be provided. The pressure-vacuum in the vessel
internal pressure between 0.1 and 0.2 MPa absolute (15 and 30 should be continuously monitored to an accuracy of 62% of
psia), and vacuum vessels having an external differential the maximum test value.
pressure between 0 and 0.06 MPa (0 and 9 psi), will normally
8. Test Preparations
be tested to pressures in the range from 1.0 to 1.5 3 operating
8.1 Safety—All plant safety requirements unique to the test
pressure.
location shall be met.
5. Significance and Use
8.1.1 Protective clothing and equipment that is normally
required in the area in which the test is being conducted shall
5.1 The AE examination method detects damage in FRP
equipment. The damage mechanisms that are detected in FRP be worn.
8.1.2 A fire permit may be needed to use the electronic
are as follows: resin cracking, fiber debonding, fiber pullout,
fiber breakage, delamination, and bond failure in assembled instrumentation.
8.1.3 Precautions shall be taken to protect against the
joints (for example, nozzles, manways, etc.). Flaws in un-
stressed areas and flaws that are structurally insignificant will consequences of catastrophic failure when pressure testing, for
example, flying debris and impact of escaping liquid. Pressur-
not generate AE.
5.2 This practice is convenient for on-line use under oper- izing under pneumatic conditions is not recommended except
when normal service loads include either a superposed gas
ating stress to determine structural integrity of in-service
equipment usually with minimal process disruption. pressure or gas pressure only. Care shall be taken to avoid
overstressing the lower section of the vessel when liquid test
5.3 Flaws located with AE should be examined by other
techniques; for example, visual, ultrasound, dye penetrant, etc., loads are used to simulate operating gas pressures.
8.1.4 Special safety precautions shall be taken when pneu-
and may be repaired and tested as appropriate. Repair proce-
dure recommendations are outside the scope of this practice. matic testing is required; for example, safety valves, etc.
8.2 Vessel Conditioning—The operating conditions for ves-
6. Basis of Application
sels that have been stressed previously shall be reduced prior to
6.1 Personnel Qualification—NDT personnel shall be testing according to the schedule shown in Table 1. The
qualified in accordance with a nationally recognized NDT maximum operating pressure or load in the vessel during the
personnel qualification practice or standard such as ANSI/ past year must be known in order to conduct the AE examina-
ASNT-CP-189, SNT-TC-1A, MIL-STD-410, or a similar docu- tion properly.
ment. The practice or standard used and its applicable revision 8.3 Vessel Stressing—Arrangements should be made to
shall be specified in the contractual agreement between the stress the vessel to the operating pressure-load where possible.
using parties. The stress rate shall be sufficient to expedite the test with
6.2 Qualification of Nondestructive Agencies—If specified minimum extraneous noise. Holding stress levels is a key
in the contractual agreement, NDT agencies shall be qualified aspect of an acoustic emission examination. Accordingly,
and evaluated in accordance with Practice E 543. The appli- provision must be made for holding the pressure-load at
cable edition of Practice E 543 shall be specified in the designated check points.
contractual agreement.
TABLE 1 Requirements for Reduced Operating Pressure-Load
6.3 Procedures and Techniques—The procedures and tech-
Immediately Prior to Testing
niques to be utilized shall be in accordance with this practice
% of Operating Time at Reduced
unless otherwise specified. Specific techniques may be speci-
Pressure or Pressure or
fied in the contractual agreement.
Load, or Both Load, or Both
10 or less 12 h
7. Instrumentation
20 18 h
7.1 The AE instrumentation consists of sensors, signal 30 30 h
40 2 days
processors, and recording equipment. Additional information
50 4 days
on AE instrumentation can be found in Practice E 750.
60 7 days
7.2 Instrumentation shall be capable of recording AE counts
E 1067
8.3.1 Atmospheric Tanks—Process liquid is the preferred fill sources. Greater attenuation of stress waves at higher frequen-
medium for atmospheric tanks. If water must replace the cies result in smaller zones of sensitivity for high-frequency
process liquid, the designer and user shall be in agreement on sensors.
the procedure to achieve acceptable stress levels. 9.4 Low-Frequency Sensor—(See Annex A1.) Low-
8.3.2 Vacuum-Tank Stressing—A controllable vacuum- frequency channels are less affected by attenuation; therefore,
pump system is required for vacuum tanks. they can be used to identify flaws in a large zone. If significant
8.3.3 Pressure-Vessel Stressing—Water is the preferred me- activity is detected on the low-frequency channels, and not on
dium for pressure tanks. Safe means for hydraulically increas- high-frequency channels, consideration should be given to
ing the pressure under controlled conditions shall be provided. relocating high-frequency sensors. It should be noted, however,
8.4 Tank Support—The tank shall be tested in its operating that low-frequency channels are more susceptible to back-
position and supported in a manner consistent with good ground noise.
installation practice. Flat-bottomed tanks tested in other than 9.5 Locations and Spacings—Locations on the vessel shell
the intended location shall be mounted on a pad (for example, are determined by the need to detect structural flaws at critical
rubber on a concrete base or equivalent) to reduce structure- sections; for example, high-stress areas, geometric discontinui-
borne noise between the tank and base. ties, nozzles, manways, repaired regions, support rings, and
8.5 Environmental—The normal minimum acceptable ves- visible flaws. Spacings are governed by the attenuation of the
sel wall temperature is 4°C (40°F). FRP material.
8.6 Noise Reduction—Noise sources in the examination 9.5.1 Attenuation Characterization—Typical signal propa-
frequency and amplitude range, such as rain, spargers, and gation losses shall be determined according to one of the
foreign objects contacting the tank, must be minimized since following procedures. These procedures provide a relative
they mask the AE signals emanating from the structure. The measure of the attenuation, but may not be representative of
inlet should be at the lowest nozzle or as near to the bottom of genuine AE activity. It should be noted that the peak amplitude
the vessel as possible, that is, below the liquid level. Liquid from a mechanical pencil lead break may vary with surface
falling, swirling, or splashing can invalidate data obtained hardness, resin condition, and cure. In both cases the attenua-
during the filling phase. tion characterization should be made above the liquid line.
8.7 Power Supply—A stable grounded power supply, meet- 9.5.1.1 For acoustic emission instrumentation with ampli-
ing the specification of the instrumentation, is required at the tude analysis: Select a representative region of the vessel away
test site. from manways, nozzles, etc. Mount a high-frequency AE
8.8 Instrumentation Settings—Settings will be determined sensor and locate points at distances of 150 mm (6 in.) and 300
as described in Annex A2. mm (12 in.) from the center of the sensor along a line parallel
to one of the principal directions of the surface fiber (if
9. Sensors
applicable). Select two additional points on the surface of the
9.1 Sensor Mounting—Refer to Practice E 650 for addi-
vessel at 150 mm (6 in.) and 300 mm (12 in.) along a line
tional information on sensor mounting. Location and spacing
inclined 45° to the direction of the original points. At each of
of the sensors are discussed in 9.5. Sensors shall be placed in
the four points, break 0.3 mm 2H leads and record peak
designated locations with a couplant between the sensor and
amplitude. All lead breaks shall be done at an angle of
test article. One recommended couplant is silicone-stopcock
approximately 30° to the surface with a 2.5 mm (0.1 in.) lead
grease. Care must be exercised to assure that adequate couplant
extension. The data shall be retained as part of the original
is applied. Sensors shall be held in place utilizing methods of
experimental record.
attachment which do not create extraneous signals. Methods of
9.5.1.2 For Systems Without Amplitude Analysis—Select a
attachment using crossed strips o
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.