Skip to product information
1 of 11

PayPal, credit cards. Download editable-PDF and invoice in 1 second!

GB/T 16508.5-2022 English PDF (GBT16508.5-2022)

GB/T 16508.5-2022 English PDF (GBT16508.5-2022)

Regular price $245.00 USD
Regular price Sale price $245.00 USD
Sale Sold out
Shipping calculated at checkout.
Quotation: In 1-minute, 24-hr self-service. Click here GB/T 16508.5-2022 to get it for Purchase Approval, Bank TT...

GB/T 16508.5-2022: Shell boilers - Part 5: Safety appurtenances and instruments

This document specifies the requirements for safety appurtenances and instruments of shell boilers, including safety valves, pressure measuring devices, water level measuring devices, temperature measuring devices, sewage and water discharge devices, safety protection and other devices. This document applies to the safety appurtenances and instruments selected for shell boilers defined in GB/T 16508.1.
GB/T 16508.5-2022
GB
NATIONAL STANDARD OF THE
PEOPLE REPUBLIC OF CHINA
ICS 27.060.30
CCS J 98
Replacing GB/T 16508.5-2013
Shell boilers - Part 5: Safety appurtenances and instruments
ISSUED ON: MARCH 09, 2022
IMPLEMENTED ON: OCTOBER 01, 2022
Issued by: State Administration for Market Regulation;
Standardization Administration of the People's Republic of China.
Table of Contents
Foreword ... 3
Introduction ... 6
1 Scope ... 8
2 Normative references ... 8
3 Terms, definitions and symbols ... 8
4 Basic requirements ... 9
5 Safety valve ... 9
6 Pressure measuring device ... 15
7 Water level measuring device ... 16
8 Temperature measuring device ... 18
9 Sewage and water discharge device ... 19
10 Safeguards and other devices ... 20
Bibliography ... 24
Shell boilers - Part 5: Safety appurtenances and instruments
1 Scope
This document specifies the requirements for safety appurtenances and instruments of shell boilers, including safety valves, pressure measuring devices, water level measuring devices, temperature measuring devices, sewage and water discharge devices, safety protection and other devices.
This document applies to the safety appurtenances and instruments selected for shell boilers defined in GB/T 16508.1.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 2900.48, Electrotechnical terminology of boilers
GB/T 12241, Safety valves - General requirements
GB/T 16508.1, Shell boilers - Part 1: General requirements
GB/T 16508.3, Shell boilers - Part 3: Design and strength calculation
GB/T 36699, Specification for liquid fuels and gaseous fuels burners of boilers NB/T 47063, Safety valves for power station
3 Terms, definitions and symbols
For the purposes of this document, the terms and definitions defined in GB/T 2900.48 and GB/T 16508.1 as well as the followings apply.
3.1 set pressure of safety valve
The set pressure at which a safety valve begins to open under operating conditions. 3.2 ignition safety time
The safety time for burner ignition flame to ignite. That is, when no ignition flame is formed, the time interval between the ignition fuel control valve getting the opening signal and the closing signal.
3.3 extinction safety time
When the burner is running, the time interval from when the flame detection device sends out the signal of flame extinguishment to when the safety shut-off valve starts to close.
4 Basic requirements
4.1 The safety appurtenances and instruments configured by the boiler shall meet the requirements for safe and reliable operation of the boiler.
4.2 The safety appurtenances and instruments configured by the boiler shall meet the requirements of relevant product standards.
4.3 All necessary parts required by boiler drawings and technical documents shall be equipped with measuring devices such as pressure, water level and temperature. The measuring device shall have an appropriate range and be safe and reliable. The measured values shall be accurate enough. Configure local and remote pressure, water level and temperature measuring devices according to the requirements of this document.
4.4 The calibration and maintenance of measuring instruments shall comply with the regulations of the national metrology management department.
5 Safety valve
5.1 Quantity and type
5.1.1 Each boiler shall be equipped with at least two safety valves (including drum and superheater safety valves). Only one safety valve may be installed if one of the following requirements is met:
a) Steam boilers with rated evaporation not greater than 0.5 t/h;
b) Steam boilers with rated evaporation less than 2 t/h and equipped with reliable overpressure interlock protection device;
c) Hot water boilers with a rated heating power no greater than 2.8 MW. 5.1.2 Steam boilers shall adopt full-open spring safety valves, lever safety valves or control safety valves (including pulse type, pneumatic type, hydraulic type and electromagnetic type, etc.). The hot water boiler can use a micro-opening safety valve. The selected safety valve shall meet the requirements of the corresponding technical transmission system.
5.4.7 The safety valve exhaust pipe of the steam boiler meets the following requirements.
a) Steam boiler safety valve shall be equipped with exhaust pipe. The exhaust pipe shall lead directly to a safe place. There shall be enough flow cross-sectional area. Ensure smooth exhaust. At the same time, the exhaust pipe shall be fixed. Avoid affecting the correct action of the safety valve due to thermal expansion or exhaust steam reaction. There shall not be any external force from the exhaust pipe applied to the safety valve.
b) The exhaust pipes of two independent safety valves shall not be connected. c) The exhaust pipe arranged in the open air shall be equipped with a protective cover. The installation of the protective cover shall not hinder the normal operation and maintenance of the safety valve.
d) When the exhaust pipe of the safety valve is equipped with a muffler, its structure shall have a sufficient flow cross-sectional area. There must be a suitable bracket and a reliable hydrophobic device.
e) The bottom of the exhaust pipe of the safety valve shall be equipped with a drainpipe connected to a safe place. Valves shall not be installed on discharge pipes and drainpipes.
5.4.8 The safety valve of the hot water boiler shall be equipped with a discharge pipe. The discharge pipe shall lead directly to a safe place. There is enough discharge flow area to ensure smooth discharge. Valves shall not be installed on the discharge pipe. Antifreeze measures shall be taken.
5.5 Use and verification
5.5.1 After the safety valve is installed (including maintenance and replacement), its set pressure and tightness shall be verified. For the control type safety valve, the reliability test of the control circuit and the opening performance test shall be carried out, respectively.
5.5.2 After the safety valve is verified, it shall be locked or sealed. The inspection results of the set pressure and tightness shall be recorded in the boiler safety technical file. 5.5.3 During the operation of the boiler, the safety valve shall not be disconnected arbitrarily; the set pressure of the safety valve shall not be increased arbitrarily, or the safety valve shall not be invalidated.
5.5.4 During the operation of the boiler, the discharge test of the safety valve shall be carried out regularly. For control type safety valves, the control system shall be tested regularly.
5.5.5 In-use boiler safety valves are verified at least once a year. Verification is generally carried out when the boiler is running. If the on-site verification is difficult or after the safety valve is repaired, it can be carried out on the safety valve verification platform. The verified safety valve shall not be dropped, smashed or collided during transportation or installation.
6 Pressure measuring device
6.1 Each boiler shall be equipped with pressure gauges at the following locations: a) in the steam space of the steam boiler shell (drum);
b) before the feed water regulating valve;
c) at the outlet of the economizer;
d) between superheater outlet and main steam valve;
e) on the shell (drum) of the hot water boiler;
f) at the outlet of water inlet valve and inlet of water outlet valve of hot water boiler; g) at the outlet and inlet of the circulating water pump of the hot water boiler; h) at the oil pump inlet (oil return) and outlet of the ignition oil system of oil-fired boilers and coal-fired boilers;
i) behind the gas source inlet of the ignition gas system of gas-fired boilers and coal- fired boilers and the pressure-regulating valve (regulator valve) of the gas valve group.
6.2 The selected pressure gauge meets the following requirements.
a) The pressure gauge accuracy shall not be lower than level 2.5. For boilers with a rated working pressure of not less than 3.8 MPa, the accuracy of the pressure gauge shall not be lower than level 1.6.
b) The range of the pressure gauge shall be selected according to the working pressure. Generally, it is 1.5~3.0 times the working pressure. It shall select 2.0 times.
c) The size of the pressure gauge dial shall ensure that the boiler operator can clearly see the pressure indication value. The dial diameter shall not be less than 100 mm. d) The pressure gauge shall be calibrated regularly. A red line indicating the working pressure shall be drawn on the dial. Indicate the date of the next verification. After the pressure gauge is verified, it shall be sealed with lead.
direct-reading water level gauge:
a) Boilers whose rated evaporation is not more than 2 t/h.
b) Boilers with two independent remote water level measurement devices. c) Electric heating boilers.
d) Through-flow boilers with a reliable wall temperature interlock protection device. 7.2 Structure, device
7.2.1 The water level gauge shall have obvious signs indicating the highest, lowest safe water level and normal water level. The upper visible edge of the water gauge shall be at least 25 mm above the highest safe water level. The lower visible edge shall be at least 50 mm higher than the highest fire circle. It shall be at least 25 mm lower than the minimum safe water level.
7.2.2 The inner diameter of the glass tube of the glass tube water level gauge shall be greater than or equal to 8 mm. The width of the visible water level shall be greater than 8 mm. To prevent safety accidents caused by damage to the glass tube, the water level gauge shall have protective devices (protective cover, quick-closing valve, automatic locking bead, etc.). However, any protective device shall not hinder the observation of the real water level.
7.2.3 A set of water level gauges consisting of two or more glass plates or mica sheets shall be able to continuously indicate the water level. The glass tube and mica sheet shall be able to be purged and replaced during boiler operation.
7.2.4 The water level gauge shall have a drain valve for flushing and a drain pipe connected to a safe discharge location.
7.2.5 The flow path diameter of the valve between the water level gauge (or water meter column) and the boiler shell (drum) shall be greater than or equal to 8 mm. The inner diameter of the steam-water connecting pipe shall be greater than or equal to 18 mm. When the length of the connecting pipe is greater than 500 mm or there is a bend, the inner diameter shall be appropriately enlarged to ensure the sensitivity and accuracy of the water level gauge.
7.2.6 The length of the connecting pipe of the water level gauge shall be as short as possible to ensure that the water level of the water level gauge is clearly visible and easy to flush. When the connecting pipe is not horizontally arranged, the condensed water in the connecting pipe on the steam side shall be able to flow to the water level gauge by itself. Ensure that condensed water does not accumulate in the pipe. The water in the water side connecting pipe shall be able to flow to the boiler shell (drum) by itself. 7.2.7 A valve shall be installed on the steam-water connecting pipe between the water level gauge (or water meter column) and the boiler shell (drum). The valve shall be in the fully open position when the boiler is running. For boilers with rated evaporation less than 0.5 t/h, valves may not be installed on the steam-water connecting pipe between the water level gauge and the boiler shell (drum).
7.3 Installation
7.3.1 The water level gauge shall be installed in a place that is easy to observe and operate and can accurately reflect the real water level of the drum. When the distance between the water level gauge and the operating ground is higher than 6000 mm, a remote water level measuring device or a water level video monitoring system shall be installed.
7.3.2 When multiple remote water level measuring devices monitor the boiler water level, their signals shall be taken out independently. There shall be two reliable remote water level measuring devices in the boiler control room. At the same time, a direct- reading water level gauge shall be guaranteed to work normally during operation. 7.3.3 The steam-water connecting pipe and other related components of the water level meter shall have good insulation.
8 Temperature measuring device
8.1 Temperature measuring points shall be installed at the corresponding parts of the boiler. The following temperatures shall be measured:
a) Steam boiler feed water temperature (except normal temperature feed water); b) Water temperature at the inlet and outlet of the hot water boiler;
c) Water temperature at the outlet of cast iron economizers and steam boiler economizers with a rated working pressure greater than 3.8 MPa;
d) Steam temperature at the superheater outlet and each stage outlet of the multi- stage superheater;
e) Steam temperature before and after the desuperheater;
f) Air preheater inlet and outlet air temperature and inlet smoke temperature; g) Smoke exhaust temperature.
8.2 For boilers with a rated evaporation capacity (or rated thermal power) not less than 20 t/h (or 14 MW), a furnace flue gas temperature measuring device shall be installed at the furnace outlet (internal combustion oil-fired gas boilers can be exempted). 8.3 The steam outlet of the steam boiler superheater and the hot water outlet of the hot water boiler with a rated thermal power not less than 7 MW shall be installed with a recording temperature measuring instrument.
8.4 For boilers with a rated evaporation capacity (or rated thermal power) not less than 20 t/h (or 14 MW), a recording type exhaust gas temperature measuring instrument shall be installed.
8.5 The range of the dial temperature measuring instrument shall be selected according to the working temperature. Generally, it is 1.5~2.0 times the working temperature. 9 Sewage and water discharge device
9.1 Drainage valves shall be installed at the bottom of steam boiler shell (drum), vertical boiler foot ring and water circulation system. Boilers with rated working pressure less than 3.8 MPa shall use quick-opening blowdown valves. The nominal diameter of the blowdown valve is generally 20 mm ~ 65 mm. The nominal diameter of the drain valve on the shell of the horizontal shell boiler shall be greater than or equal to 40 mm. 9.2 For steam boilers with a rated evaporation greater than 1 t/h and hot water boilers with a rated working pressure of less than 3.8 MPa and a rated outlet water temperature of not less than 120??C (except tubular boilers), two valves in series shall be installed on the sewage pipe. At least one of them is a blowdown valve, which is installed on the side close to the outlet of the blowdown pipeline.
9.3 The steam boiler shell (drum) with a superheater shall be equipped with a continuous sewage discharge device. A water discharge valve shall be installed at the lowest header (or pipeline) of the superheater system and economizer system. 9.4 Each boiler shall be equipped with an independent sewage pipe. The sewage pipe shall minimize the number of elbows to ensure smooth sewage discharge. Connect it to a safe place or sewage expansion tank (expansion vessel). When multiple boilers share one discharge header, more than 2 boilers shall be prevented from discharging sewage at the same time.
9.5 The outlet pipe of the hot water boiler is generally located at the highest point of the boiler. An air collecting device, or an automatic exhaust valve shall be installed at the highest point of the outlet pipe before the outlet valve. An exhaust valve with a nominal diameter of not less than 20 mm shall be installed at the highest point of each circuit and the highest point of the pot shell (drum) or on the outlet pipe. The exhaust pipes at the highest point of each circuit shall be arranged in a centralized manner. 9.6 A relief pipe shall be installed at the highest point of the shell (drum) of the hot water boiler or on the outlet pipe. Its inner diameter shall be determined according to the rated thermal power of the boiler, which shall not be less than 25 mm. A relief valve shall be installed on the relief pipe. When the boiler is in normal operation, the relief valve is closed. For boilers equipped with relief valves, exhaust valves may not be installed on the boiler shell (drum) or outlet pipe.
power is not less than 7 MW. The rated outlet water temperature is greater than 95??C and less than 120??C.
10.1.5 The interlock protection device shall not be out of operation at will during the operation of the boiler. The backup power supply or air source of the interlock protection device shall be reliable. The standby shall not be withdrawn arbitrarily. The standby power supply or self-injection test of gas shall be carried out regularly. 10.1.6 When two or more boilers share one main flue, a reliable flue baffle with a limit device shall be installed in the branch flue of each boiler.
10.1.7 The valves on the boiler pipes and the baffles of the smoke and air system shall have obvious signs to indicate the name, number, switch direction and medium flow direction of valves and baffles. The main regulating valve shall also have an opening indication.
10.1.8 The operating mechanisms of valves and baffles shall be installed in places that are convenient for operation.
10.2 Layer fired boiler
10.2.1 The mechanical layer fired boiler shall be equipped with an interlock protection device for failure of the combustion system. When any of the following situations occurs during operation, the air supply and fuel delivery shall be stopped urgently: a) Safety protection device fails;
b) Combustion equipment or slag removal equipment fails;
c) Blower or induced draft fan is not working properly;
d) Backfire occurs in the feeding device of the biomass layer combustion system; e) Control parameters related to boiler safety (such as water level, temperature, pressure, etc.) exceed the limit.
10.2.2 Effective measures to prevent backfire shall be taken in the biomass fuel combustion system and feeding system. The feeding device between the fuel bunker and the combustion chamber shall be interlocked with the boiler fan. A steam boiler with a rated evaporation greater than 4 t/h or a hot water boiler with a rated thermal power greater than 2.8 MW shall be equipped with a furnace negative pressure alarm device. The upper part of the combustion chamber shall be provided with a release device with an interlock function.
10.2.3 The layer fired hot water boiler shall be equipped with a device that can automatically cut off the air supply or induction when the pressure drops to the point where vaporization occurs or the water temperature exceeds the specified value, and the circulating water pump suddenly stops running, and the backup pump fails to start normally.
10.3 Chamber fired boiler
10.3.1 Chamber fired boilers shall be equipped with ignition program control devices and flameout protection devices. They shall meet the following requirements: a) In the ignition program control, the total ventilation volume before ignition shall be greater than or equal to 3 times the total volume of the flue from the furnace to the chimney inlet. The ventilation time of liquid fuel...

View full details