MERCER VALVE 91-06D51T14I1 safety valve

MERCER VALVE 91-06D51T14I1 safety valve

MERCER VALVE 91-06D51T14I1 safety valve

Working principle of safety valve

Classification of safety valves:

There are several classification methods for safety valves, including:

(1) According to the overall structure and loading structure, it can be divided into three types: heavy hammer lever type, spring type, and control type;

(2) According to the ratio of the valve disc opening height to the valve flow diameter, it can be divided into two types: micro opening and full opening safety valves;

(3) According to the method of gas emission, it can be divided into three types: fully enclosed, semi enclosed, and open.

Working principle of safety valve:

A safety valve is used on pressurized equipment, containers, or pipelines as a system overpressure protection device. When the pressure inside the equipment, container or pipeline exceeds the allowable value, the valve will automatically open and then discharge the full amount to prevent the pressure inside the equipment, container or pipeline from continuing to rise; When the pressure drops to the specified value, the valve should automatically and promptly close to protect the safe operation of equipment, containers, or pipelines.

The working principle of the illustrated safety valve

Working principle of safety valve sealing and opening:

1. Principle of direct acting safety valve:

This type of safety valve relies directly on the force generated by the medium pressure to overcome the mechanical load acting on the valve disc and open it. The mechanical load acting on the valve disc mainly comes from heavy hammers or springs, which are almost fixed mechanical loads. To ensure the sealing performance of the safety valve, strict requirements must be placed on the flatness and surface roughness of the valve seat sealing surface and valve disc sealing surface. Although sealing can be achieved by adjusting the spring force for compression spring loaded safety valves, there are strict requirements for sealing pressure difference.

The sealing pressure difference is the difference between the set pressure and the working pressure. The sealing pressure difference must be high enough to ensure sufficient sealing force, so as to achieve sealing during normal operation of the device. The sealing pressure difference should also be less than the opening and closing pressure difference to ensure that the safety valve opens at a pressure higher than the working pressure.

The recommended minimum sealing pressure difference is usually 10% of the set pressure when the working pressure is less than or equal to 7MPa, but not less than 35kPa; When the working pressure is less than 7MPa, it is 7% of the set pressure. For metal sealed safety valves, if used in toxic, corrosive, low-temperature, or particularly valuable media, or when the system pressure fluctuates as in the outlet pipeline of reciprocating pumps or compressors, it may be necessary to increase the sealing pressure difference.

In addition, the opening and closing pressure difference of safety valves used for gas or steam can be higher than 15%; The safety valve used for liquids can be higher than 20%, therefore, in order for the safety valve to close at a pressure not lower than the working pressure, the sealing pressure difference must be correspondingly increased.

The opening and closing pressure difference is the difference between the set pressure and the reseating pressure. From an economic perspective, the opening and closing pressure difference should be as small as possible to avoid unnecessary medium loss. But from the perspective of the stability of the safety valve action, it is also desirable to have a large opening and closing pressure difference. Therefore, only a compromise approach can be taken.

2. Principle of pilot operated safety valve:

A pilot operated safety valve consists of a main safety valve and a pilot valve (direct acting safety valve). The main valve is a true safety valve, while the pilot valve is used to sense the pressure of the pressurized system and open and close the main valve.

To ensure the sealing performance and other performance indicators of the pilot operated safety valve, there are strict requirements not only for the flatness and surface roughness of the valve seat sealing surface and valve disc sealing surface of the main valve, but also for the geometric dimensions, materials, and heat treatment of the compression spring. This is the only way to meet the requirements of sealing pressure ratio.

To maintain the closing force of the main valve and operate the main valve and pilot valve, energy may come from the system medium, an external energy source, or both. When the system pressure test exceeds a set limit value, the pilot valve or the system medium forces the main valve to open by removing or reducing the closing force; Or generate a force to open the main valve. After the system pressure decreases, the pilot valve generates a closing force again or eliminates the opening force. According to this opening and closing mode, a large closing force can be maintained before the safety valve opens.

Therefore, pilot operated safety valves can maintain high sealing performance even when operating at pressures close to the set pressure. The magnitude of the closing force of a pilot operated safety valve before it is about to open may not be limited, but for certain structures of pilot operated safety valves, it may also be limited by selection.

The so-called closing force is limited, which means that once the pilot valve fails, the system pressure can cause the main valve to open within the allowable pressure range. For pilot operated safety valves with limited closing force, their installation requirements are usually not as strict as those with infinite closing force. The acquisition of operating media, from the perspective of easy accessibility, is nothing more important than the system media itself. However, the pilot valve must be designed to adapt to the medium under operating conditions.

The working principle of the main safety valve: The main valve can be designed to open in two forms as the pilot valve is supplied with energy or loses energy. If the principle of power supply opening is adopted. In the event of an accident causing the pilot valve to lose energy, the main valve will remain closed. Therefore, it is appropriate to use system media as the operating medium in such situations. However, certain regulations also allow the use of external operating media. As long as these operating media are supplied by several independent energy sources, or as long as the load of the pilot safety valve is limited, if the principle of failure opening is adopted, depending on the design structure of the pilot safety valve, the failure of the pilot valve will cause the main valve to automatically open when it is lower than or equal to the set pressure. Therefore, in this case, the failure protection operation of the main valve will not be affected by the operating medium.

The working principle of a pilot safety valve: The pilot valve can be designed in two forms to open (discharge) the main valve as it is supplied with energy or loses energy. If the principle of energy supply and release is adopted, in the event of an accident and energy loss, the main valve will remain closed. Therefore, the pilot operated safety valve used in this situation uses the system medium as the operating medium. However, certain regulations also allow the use of external operating media, as long as these operating media are supplied by several independent energy sources, or as long as the load of the pilot operated safety valve is limited. If the principle of energy release is adopted, the energy release will cause the main valve to open. So in this case, the failure protection operation of the pilot valve will not be affected by the operating medium.

MTS RHM0300MD701S1B1100

FESTO SE-3/8-B

Barcontrol HDS-1-200-K-7-1 pressure switch

Radio Energy Item No.: TFR106c，Type: RE.0 444 R1 C/CA 编码器 速度感应器 E. KRETZSCHMAR Drive and Process Technology Development and Sales GmbH

Parker 3349111281 PGP511A0190CK1H2NE5E3B1B1 gear pump

Balluff GmbH BSP B250-EV002-D00A0B-S4 pressure transmitter INTECH AUTOMAZIONE srl

Hydac EDS 346-1-250-000 pressure sensor

Turck NI2-Q6,5-AP6-0,1-FS4.4X3/S304 Nr: 1650048 bus module

Norelem 02006-708 * 040 workpiece fixture

STROMAG 227-03532 Typ: NFF 25/37 Brake

STOEFFL RUDOLF ST4575-90100 liner

TR CE65M Art. Nr: 110-02872 Encoder

KUKA 128358

SIEMENS 6DD1681-0GK0 module

SCHNEIDER XS5L81PA140S proximity switch

Fezer SP-FSD200S-NOR-G Item No. :1.11.1.0068 Suction cup

EPE 210P10-AOO-O-PM filter cartridge

Hydac EDS344-3-250-000 pressure sensor

PULS Electronic GmbH Art. Nr.QS20.241 Power Supply PULS Electronic GmbH

Colortronic 4211150 hopper

Hydac KHM-40-F6-11141-06X ball valve

brinkmann TH426A590+593 （TH45/543+593） 潜水泵 K. H. Brinkmann GmbH & Co. KG

AUTRONICA BSL-330/2

LEYBOLD DI2000

INFICON 12216

INA ABAL 52 side baffle

BALLUFF BIS C-122-04/L

Maag 056 MAK11-6D， 0190 630152 Gear Pump Parts - Magnetic Coupling

BAUMER CH-8500 Frauenfeld FZDK 26R7101

Ac motoren IE2AC28S4000 Nr.03102535 motor

GMT GmbH D25/H17/M6x18 K/D55100102 connector

Norelem 07534-06x20 screw

EMOD motor TM63S/4T

Specken drum AB-0900 wiring terminal

Dopag 418.01.00 阀

Badger 1002GCG36sk0sbln36 process control valve

Elektro-Maschinenbau Ettlingen GmbH 4625201099 electric motor

DUNGS W-MF 512 C01

hengstlerAC58/1212EF.47PBB-D0

RADIO-ENERGIE Ref 444R1ATEXBCA

Helios C/RK/3/G1 1/2-3000W heater

B&R Industrie Elektronik GmbH 8V1090.00-2 Bus Module

HYDAC DFZ BH/HC 30 Q B 3 LZ 1.0 /-BO

Soler & Palau HRT/4-500/35BPN, 230V/400V C V3,NO:5700147100

MRS Electronic STECKERPAKET FUR M2600 CAN SPS Nr.108888 Equipment Accessories

HYDAC 0660 R 005 BN4HC NR. 1263016 Filter Cartridge

Staubli K4N001722

Rexroth DREE10-6X/315YMG24K31A1M pressure reducing valve

Euchner TX1C-A024RC18 Nr.82934 Automatic Controller

BREVINI M14000002

ATOS DKE-1711/FI/N0-24DC Valve

MTS RHM0450MD531P102 with M magnet

Schonbuch ICDA 6514 Inductive Sensor

Murrelektronik GmbH 9000-41034-0100600 Bus Module

Cosmotec TB350002200W00 Top Ventilation Hood

KPM DE6P-30-204-WD24CL

Catu E - M-87-295

Bosch Rexroth 820055601 solenoid valve

rexroth LHPE-102-L50V-EX

BECKHOFF CP9904

P+F EPV-2-SA-90, Artikelnr. 513148 proximity switch

Hilma 9.3583.7010 torque wrench

Murr MCS20-3X400/24, Nr: 85097 power module power Puettmann KG

ZIEHL-ABEGG RG28P-4EK.41.1R10169467

Hongsberg RW-015HKS liquid level switch liquid level sensor Hongsberg

SIEMENS 6EP1436-3BA00 power module

CROUZET Single Pulse Generator 81507720

WATLOW CONTROLLER POWER DC21-60K2-0000

DUESTERLOH PMW160Z24PF-A200-PD2010Z i=11.42 2.8kw 马达

Turck BL20-P3T-SBB Nr: 6827036 bus module

HAHN+KOLB 53091 130

TWK GRF05B-FK-01

G-BEE 33.1 3/4 'Ball Valve G-BEE

INFASTAUB ESM-346 R

Stauff Pipe clamp SPAL3016 AL DPAL-AS SI M W23

Bussmann - JJN 100

KATKO KEM 3400 Y/R

Fotoelektrik Pauly GmbH&Co. KG PS20R26/1PG9/y/p1 Grating Encoder Grating Encoder Fotoelektrik Pauly GmbH&Co. KG

PHOENIXRU2S-A220+base

Demag Cranes & Components GmbH VE 150-500V AC , 26090284 relay

Rittal 4155100 lighting fixture

ENDEVCO tension sensor 2313

SAILSORS NO.SC141016102A

WILDEN 01-3181-20

Bender IR470LY-4,B910