SNT - THROUGH WAY DRAIN VALVE 3/4"(DN20)~3"(DN80)ANSI Class 150~2500
Applications |
-Steam boiler, evaporator and other boiler water continuous drain control -Flow and pressure regulation and flash application -Steam boiler, evaporator and other boiler water intermittent drain control |
Manual operation control Pneumatic operation control Electric operation control |
Nominal pressure |
ANSI 150, 300, 600, 900, 1500, 2500 |
Pressure class >=ANSI 1500 for RT testing |
Nominal diameter |
Forging mode |
3/4"(DN20), 1"(DN25) and 1.1/2"(DN40), 2"(DN50) |
ANSI 150, 300, 600, 900, 1500, 2500 |
Casting mode |
2.1/2 "(DN65), 3"(DN80) |
ANSI 150, 300, 600, 900, 1500 |
Connection mode |
Forging mode |
-Standard connection: SW -Optional connection: BW or flanged |
|
Casting mode |
-ANSI900 and below use flange connections ANSI1500 and above are butt welded connections - Cap of Angle and straight through body: bolted |
Metal self-sealing structure for option |
Design calculation |
- Through way type GLOBE valve - Split valve is convenient for operation and maintenance - Multistage pressure drop valve internals (SNT standard design application) - The size of the seat hole is calculated by strict design - Verified by CFD analysis and testing - Compound hole plate can be configured for actual high pressure difference conditions - Suitable for forging and bar stock - Heat treatment of valve internals Valve core: surface hardening or nitriding treatment Seat: nitriding or surfacing with STL alloy |
Replace seat and core quickly No venturi applications CFD simulation method: FLUENT Other hole types: Conical hole/labyrinth flow channel The maximum pressure rating for bar design is: >=ANSI1500 Surface hardening: surfacing STELLITE Gr.6 Surface hardening of seat: Other options |
Materials |
- Carbon steel - Alloy steel - Stainless steel - High quality Alloy steel |
A105 A182-F11/F22 A182-F304(L) A182-F316(L) As required by customer |
|
Flow control |
- Continuous flow control conditions - Intermittent flow control condition |
Pneumatic, electric or manual control |
No. |
Part name |
Standard material |
No. |
Part name |
Standard material |
<ANSI 900 |
>=ANS|1500 |
<ANSI900 |
>=ANSI 1500 |
1 |
Valve body |
A105N |
A105N |
83 |
Screw holder |
HBsc2 |
HBsc2 |
2 |
Top cover |
A105N |
A105N |
85 |
Flat head round key |
Carbon steel |
Carbon steel |
3 |
Body screw |
A193-B7 Colored zinc plating |
A193-B7 Colored zinc plating |
86 |
Lock nut |
Carbon steel + galvanized |
Carbon steel + galvanized |
4 |
Body nut |
A194-2H Colored zinc plating |
A194-2H Color zinc plating |
87 |
Hex socket screws |
304SS |
304SS |
5 |
Valve core |
A276410+HF |
316+S503+S505 |
88 |
Nameplate |
304SS |
304SS |
6 |
Valve seat |
A276410+HF |
316+ZY08 |
89 |
Connecting flange |
Carbon steel |
Carbon steel |
8 |
Wrap shims |
304+GRAPHITE |
304+GRAPHITE |
90 |
Limit anti-turn block |
Carbon steel + galvanized |
Carbon steel + galvanized |
9 |
Sleeve |
440C+HF |
316+S101 |
91 |
Nuts |
Carbon steel + galvanized |
Carbon steel + galvanized |
14 |
Wrap shims |
304+GRAPHITE |
304+GRAPHITE |
92 |
Thrust needle roller bearings |
Bearing steel (standard material |
Bearing steel (standard material |
17 |
Packing plate |
A351 CF8 |
A351 CF8 |
93 |
Hex set screws |
304SS |
304SS |
23 |
Nuts |
A194-2H |
A194-2H |
252 |
Packing gland |
A276410 |
A276410 |
24 |
Screw |
A193-B7 |
A193-B7 |
255 |
Packing assembly |
Flexible graphite |
Flexible graphite |
80 |
Support stand pole |
Carbon steel + galvanized |
Carbon steel + galvanized |
257 |
Packing pad |
A276410 |
A276410 |
81 |
Hex head bolts |
304SS |
304SS |
572 |
Handwheel |
Carbon steel |
Carbon steel |
Notes:
1.S101 hard surface technical description: HRC≥55, metallurgical combination, not easy to fall out;
2.S503 hard surface technical description: thickness 1.5mm, hardness HRC≥55, binding force 400MPa, not easy to fall out;
3.S505 hard surface technical description: thickness 0.3mm, hardness HRC≥65, binding force ≥250MPa;
About SNT Blow-down Valves
SNT Machinery(Qingdao) Co., Ltd. (referred to as SNT) is a valve manufacturing company that specialized in the development, design and production of fluid flow and valve technology.
SNT drain valve can be widely used in continuous throttling control, such as: boiler continuous drain, high pressure vessel and reactor sampling, high pressure discharge, boiler feed pump bypass system release device, high pressure difference (pressure release) conditions, heater drain to the condenser process due to corrosion and high flow rate flash conditions. Compared with the traditional valve, the SNT valve is more robust and durable, which is suitable for continuous drain conditions that can cause serious damage to the valve. Because in the continuous drain working condition, the flow rate is high, the erosion is more serious, the traditional cutoff drain valve is fragile, even the venturi valve is also fragile.
The SNT drain valve breaks the traditional internal structure design concept. The flow channel between the valve core and the cylindrical valve seat adopts smooth design, which can accelerate the fluid flow until the fluid reaches the downstream of the valve seat, and the chamber suddenly becomes larger. At this time, the pressure drop caused by the center part of the flow channel leads to the rapid expansion of the fluid toward the flow center part. While the energy of the fluid flow also quickly disperses and evaporates, and the fluid enters turbulent condition. The efficient discharge process ensures that the fluid can form steam when supersaturated, while cooling the remaining liquid, which is a typical way to use flash evaporation in liquid flow.
In order to meet the various needs of the device, we can produce valves in the pressure range of ANSI 150 to ANSI 2500. Standard stop valve size is 3/4"(DN20), 1"(DN25), 1.1/2"(DN40), 2"(DN50), 2-1/2"(DN65) and 3"(DN80). The standard form of SNT valve is angular connection, to allow a uniform flow of fluid.The through way type stop valves are also available. According to the control, it can be divided into manual, pneumatic and electric control. For accurate throttling control, based on the flow evaluation in the SNT internal-design structure, the Fluent-Code of a computational Fluid Dynamics is used to simulate and analyze the flow channel and its pressure drop. All SNT internals are usually surface-hardened with high-quality Co-Ni based alloys or surface-treated with Cr-N ceramic coatings to prevent abrasion and corrosion due to high pressure drops and flow rates.
Rated flow coefficient comparison table
Application of Typical Working Conditions
As shown in the figure on the left, according to ASME B31.1 Power Boilers and Piping, intermittent drain valves are usually used in Zone 2 and are installed directly in boiler or boiler piping. There are also continuous drain valves, traps, and safety valves, etc.
According to §122.1.4 of ASME B31.1 Power Boilers and Piping, the piping is usually fitted with 2 valves in series, a Y-type intermittent drain valve and an emergency stop valve.
The intermittent drain valve usually adopts the lever type rapid discharge mechanism, which can realize the rapid opening and closing. When the valve is opened, the sediment, dirt and other particles at the bottom of the boiler can be discharged quickly, no more than 3S. If the time is too long, a large amount of boiler water will be discharged, resulting in a great waste of resources. The flow channel is close to the straight pipeline.
The emergency stop valve is used to realize the strict cut-off of the pipeline and prevent the waste of resources when the previous intermittent drain valve fails.
Pressure and Temprature Parameters
![Alloy Steel ANSI 150~1500 High Pressure & Temperature Through Way Type Boiler Blow-Down Valve](//www.micstatic.com/athena/img/transparent.png)
SNT Ball Valves are meticulously engineered to comply with a multitude of international standards, including ASME B16.34-2009, ASME B16.10-2000, and API 589-2009. This versatile series finds extensive applications across various industries such as petroleum, chemical industry, light industry, pharmaceuticals, paper-making, metallurgy, and power stations.
Their Outstanding Features Include:
Streamlined design for effortless disassembly.
Designed with ease of maintenance in mind, our ball valves feature a non-tight fit design that facilitates quick servicing, minimizing downtime during periodic maintenance.
Cutting-edge sealing technology for maximum security.
The multi-layer sealing of stem and body delivers dual protection through a combination of O-ring and graphite or PTFE, ensuring exceptional sealing performance.
This innovative design meets the rigorous TA-Luft/Shell SPE 77/312 standards.
Extended Service Life for Superior Cost-Efficiency
Our metal seated ball valves undergo advanced processing techniques such as spray welding, spraying, and fusion welding. This guarantees a hardness range of HRC58-73 and a binding force of 80-40MPa, with an impressive on-off cycle lifespan exceeding 100,000 operations and a leakage class of ANSI VI.
Modular Design for Enhanced Convenience
The modular inner sealing design allows for easy interchangeability between soft and metal seats, ensuring flexibility and reliability.
Varied Connection Types for User Convenience
Our valves are available in various connection types, including flanged (RF, FF, FM, G, RJ), screw-thread, and BW, all of which conform to international standards, providing seamless and user-friendly integration.
Extensive Application Experience Guarantees Reliability
SNT Valves have earned a stellar reputation through widespread use in petroleum, chemical industry, light industry, pharmaceuticals, paper-making, metallurgy, and power stations. We deliver optimal solutions tailored to specific service conditions, ensuring market-leading reliability.