GB 20952-2007 English PDF

Delivery: 2 working-hours manually (Sales@ChineseStandard.net)
Need delivered in 3-second? USA-Site: GB 20952-2007
Get Quotation: Click GB 20952-2007 (Self-service in 1-minute)
Historical versions (Master-website): GB 20952-2007
Preview True-PDF (Reload/Scroll-down if blank)

GB 20952-2007: Emission standard of air pollutant for gasoline filling stations
GB 20952-2007
NATIONAL STANDARD OF THE
PEOPLE?€?S REPUBLIC OF CHINA
ICS 13.040.40
Z 60
Emission standard of air pollutant for gasoline filling
stations
ISSUED ON: JUNE 22, 2007
IMPLEMENTED ON: AUGUST 01, 2007
Issued by: State Environmental Protection Administration;
General Administration of Quality Supervision, Inspection and
Quarantine.
Table of Contents
Foreword ... 4??
1 Scope ... 5??
2 Normative references ... 5??
3 Terms and definitions ... 5??
4 Gasoline vapor emission control and limit ... 7??
5 Technical measures ... 11??
6 Standard implementations ... 13??
Annex A (normative) Testing methods for liquid resistance ... 15??
Annex B (normative) Testing methods for vapor recovery system tightness .. 19??
Annex C (normative) Testing methods for air to liquid volume ratio ... 24??
Annex D (normative) Testing methods for vapor emission processing equipment
... 33??
Annex E (informative) Calibration method for on-line monitoring system ... 36??
Annex F (informative) Testing report of gasoline filling station ... 39??
Emission standard of air pollutant for gasoline filling
stations
1 Scope
This Standard specifies gasoline vapor emission limits of gasoline filling
stations, control technical requirements and testing methods.
This Standard is applicable to gasoline vapor emission management of existing
gasoline filling stations as well as environmental impact assessment, design,
completion acceptance of new, modified and expanded gasoline filling station
projects and gasoline vapor emission management after completion.
2 Normative references
The provisions in the following documents become part of this Standard,
through reference in this Standard. For undated documents, the latest version
applies to this Standard.
GB 50156, Code for design and construction of automobile gasoline and gas
filling station
GB/T 16157 The determination of particulates and sampling methods of
gaseous pollutants emitted from exhaust gas of stationary source
HJ/T 38 Stationary source emission - Determination of nonmethane
hydrocarbons - Gas chromatography
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 gasoline filling station
A special place for filling gasoline into car fuel tank.
3.2 gasoline vapor
Volatile organic compounds (non-methane total hydrocarbons) generated
during the filling, unloading and storage of gasoline at gasoline filling stations.
3.3 vapor emission concentration
Under standard conditions (temperature is 273K, pressure is 101.3kPa), the
mass of non-methane total hydrocarbons contained in every m3 of dry gas
discharged, in g/m3.
3.4 vapor recovery system for gasoline filling station
A vapor recovery system for gasoline filling station is composed of vapor
recovery system for unloading, closed storage of gasoline, vapor recovery
system for filling, online monitoring system, and vapor emission processing
equipment. The role of this system is to TRANSFER the gasoline vapor
generated during the unloading, storage and filling of the gasoline filling station,
through closed collection, storage and sending into the tank of a tank car, and
TRANSPORT to the oil storage depot for centralized recovery into gasoline.
3.5 vapor recovery system for unloading gasoline
A system that collects the gasoline vapor generated when a tank car unloads
gasoline, through a closed manner, into the tank of the tank car.
3.6 vapor recovery system for filling gasoline
A system that collects the gasoline vapor generated when a tank car fills
gasoline, through a closed manner, into the underground storage tank.
3.7 overfill protection measurement
The overfill that might happen when controlling gasoline unloading by using
shut-off valve or float valve or other anti-overflow measures.
3.8 underground storage tank
A fully-buried storage tank under the ground.
3.9 pressure/vacuum valve
Also known as P/V valve, vent valve, mechanical breathing valve, which can
adjust the pressure difference between the inside and outside of the tank so
that the gas inside and outside the tank can communicate.
3.10 dynamic back pressure
The resistance when condensate liquid stays in the gasoline vapor pipeline or
causes gas to pass through the pipeline for other reasons.
3.11 vapor recovery system tightness
The sealing degree of vapor recovery system under certain gas pressure.
3.12 air to liquid volume ratio
The ratio of the volume of gasoline vapor collected when filling to the volume of
gasoline added to the tank at the same time.
3.13 vacuum-assist
In the vapor recovery system for filling gasoline, use the vacuum generator to
assistant recovering the gasoline vapor generated during gasoline filling.
3.14 on-line monitoring system
The system that online monitors whether the air to liquid volume ratio in the
vapor recovery process for filling gasoline as well as the vapor recovery system
tightness of the vapor recovery system and pipeline liquid resistance are normal.
When abnormality is found, it can remind the operator to take corresponding
measures, and can record, store, process and transmit monitoring data.
3.15 vapor emission processing equipment
The device that recovers the gasoline vapor discharged from the vapor
recovery system for gasoline filling station, through methods such as attaching,
absorption, condensation, membrane separation.
4 Gasoline vapor emission control and limit
4.1 The gasoline vapor emitted during unloading, storing and filling of gasoline
filling station shall use the gasoline vapor recovery method based on closed
collection to control.
4.2 Technical assessment
4.2.1 The vapor recovery system for filling gasoline shall conduct technical
assessment and issue a report. The assessment mainly includes: investigating
and analyzing technical information, verifying relevant certification documents,
evaluating air to liquid volume ratio of multiple flows and guns, testing
operations of at least 3 months in concession, providing rang of air to liquid
volume ratio of which the control efficiency is greater than or equal to 90%,
listing equipment of vapor recovery system.
4.2.2 The vapor emission processing equipment (hereinafter referred to as the
processing equipment) and on-line monitoring system shall conduct technical
assessment and issue a report. The assessment mainly includes: investigating
and analyzing technical information, verifying relevant certification documents,
providing proof of actual use in China or abroad, testing operations of at least
3 months in concession.
5 Technical measures
5.1 Emission control of gasoline vapor of unloading gasoline
5.1.1 It shall use submersible unloading method. The height of the gasoline
outlet of the unloading pipe from the bottom of the tank shall be less than
200mm.
5.1.2 The gasoline unloading and oil recovery interface shall be installed with
DN100mm shut-off valve, sealed quick connector and cap. For the exiting
gasoline filling stations, if unloading emission control measures have been
taken but the interface size does not match, it may use a reducing diameter one
to connect.
5.1.3 The connecting hose shall be connected to the unloading truck with a
DN100mm sealed quick connector. No residual oil can be left in the connecting
hose after unloading.
5.1.4 All gasoline vapor pipeline emission ports shall be equipped with
pressure/vacuum valves according to the requirements of GB 50156.
5.1.5 The underground pipeline connected to the exhaust pipe shall slope to
the oil tank. The slope shall not be less than 1%. The pipeline diameter is not
less than DN50mm.
5.1.6 For gasoline filling stations that have not taken technical measures for
filling and storage of gasoline vapor recovery, when unloading, the gasoline
measuring hole and other parts that may cause gas short circuit shall be sealed,
so as to ensure that the gasoline vapor generated by unloading gasoline is
sealed and replaced in the tank of tank car.
5.2 Gasoline vapor emission control of gasoline storage
5.2.1 All components that affect the tightness of gasoline vapor stored, including
gasoline vapor pipelines and connected flanges, valves, quick couplings, and
other related components shall be guaranteed to be free of air leakage when
less than 750Pa.
5.2.2 The underground storage tank shall use electronic liquid level gauge to
measure the tightness of gasoline. The electronic liquid level measurement
system with leak detection function shall be selected.
5.2.3 It shall adopt overfill protection measurements that meet relevant
requirements.
5.3 Emission control of vapor recovery for filling gasoline
Annex A
(normative)
Testing methods for liquid resistance
A.1 Application scope
This appendix is applicable to the liquid resistance testing of the underground
vapor recovery pipeline from the gasoline dispenser to underground storage
tank. It shall test the liquid resistance of the underground vapor recovery
pipeline from each gasoline dispenser to underground storage tank.
Special attention: the regulations on safety production of gasoline filling stations shall be
strictly implemented during testing.
A.2 Testing principle and overview
A.2.1 Fill the vapor recovery pipeline with nitrogen at the specified nitrogen flow.
Simulate gasoline vapor through gasoline vapor recovery pipelines.
A.2.2 Use a pressure gauge or equivalent device to detect the liquid resistance
of the gas through the pipeline. Know the degree of resistance to gas in the
pipeline due to various reasons and use to judge whether it shall affect the
vapor recovery.
A.3 Deviation and interference
A.3.1 Any leaks in the relevant vapor pipelines shall result in low fluid resistance
measurement.
A.3.2 If it starts testing when nitrogen flow stabilizes less than 30s, it shall
produce erroneous liquid resistance measurement.
A.4 Testing equipment
A.4.1 Nitrogen and nitrogen bottles. Uses commercial grade nitrogen, high-
pressure nitrogen cylinder with two-level pressure regulator and a 6.9kPa relief
valve.
A.4.2 Pressure gauge. Use the pressure gauge described in A.5.1, A.5.2 and
A.5.3.
A.4.3 Float flowmeter. Use the float flowmeter described in A.5.4. It and the
pressure gauge shall form the testing equipment for liquid resistance (see
Figure A.1).
A.6 Testing procedures
A.6.1 Open the bottom pot of the gasoline dispenser being tested. Find the
three-way and testing joints reserved on the vapor recovery riser pipe for filling
gasoline.
A.6.2 Connect the liquid resistance testing device to the three-way testing
connector through a hose.
A.6.3 Ground the nitrogen bottle. Connect the nitrogen pipe to the nitrogen inlet
connector of the liquid resistance testing device.
A.6.4 Open the vapor interface valve of vapor recovery system for unloading
gasoline of corresponding tank.
A.6.5 If testing new, modified and expanded gasoline filling stations, 10L
gasoline shall be injected into the pipeline before soil coverage on vapor
pipelines and ground hardening construction.
A.6.6 Turn on the nitrogen bottle. Set the pressure of the low-pressure regulator
to 35kPa. Use a float flow control valve to regulate the nitrogen flow. Starting
with the lowest nitrogen flow in Table 1, respectively test the liquid resistance
corresponding to 3 flows. Before reading the pressure gauge value, the nitrogen
flow shall be stable for more than 30s.
A.6.7 If any one of the three liquid-resistance tested values is greater than the
maximum pressure limit specified in Table 1, the liquid resistance of the
gasoline filling station shall be nonconforming. If the test value cannot be
determined due to the jitter of the pressure gauge, the liquid resistance test is
deemed nonconforming.
A.6.8 Remove the hose connected to the three-way testing connector. Restore
the connection of the original vapor recovery pipeline.
A.6.9 Close the vapor interface valve of the corresponding tank.
A.7 Testing record
See Table F.1 in Annex F for liquid resistance testing result record of vapor
recovery pipelines.
which shall affect the vapor recovery system tightness testing of the entire
system, it shall set up a short-circuit pipeline with a shut-off valve.
B.4 Testing equipment
B.4.1 Nitrogen and nitrogen bottle, same with A.4.1.
B.4.2 Pressure gauge. Use the pressure gauge described in B.5.1 and B.5.2.
B.4.3 Float flowmeter. Same with A.4.3. It and the pressure gauge shall form
the testing device for vapor recovery system tightness (see Figure A.1).
B.4.4 Stopwatch. Same with A.4.4.
B.4.5 Three-way testing connector. Same with A.4.5.
B.4.6 Hose. Same with A.4.6.
B.4.7 Grounding device. Same with A.4.7.
B.4.8 Leak detection solution. Any solution that can be used to detect gas leaks,
used to inspect the vapor recovery system tightness of system components.
B.5 Sensitivity, range and accuracy
B.5.1 The minimum diameter of mechanical pressure gauge dial is 100mm. The
measuring range is 0~750Pa. The accuracy is 2% of full measuring range. The
minimum scale is 25Pa.
B.5.2 When the full measuring range of electronic pressure measuring device
is 0~2.5kPa, the accuracy is 0.5% of full measuring range. When the full
measuring range is 0~5.0kPa, the accuracy is 0.25% of full measuring range.
B.5.3 The minimum vapor space of a single oil tank shall be 3800L or 25% of
the volume of the oil tank. Take the smaller value of the two. The maximum total
vapor space to connect the oil tank shall not exceed 95000L. The above does
not include the volume of all vapor pipelines.
B.5.4 The flow rate of filled nitrogen is 30~100L/min.
B.5.5 Float flowmeter is the same as A.5.4.
B.5.6 Stopwatch same as A.5.5.
B.5.7 All measuring instruments shall be calibrated according to measuring
standards.
B.6 Procedures before testing
calibration point. The calibration frequency shall not exceed 90d.
B.6.8 Use formula B.1 to calcu...