Skype: jeany5678 ------ What's app:86 151 5776 6245 ------ Email: [email protected]

Archive for category: Industry News

You are here: Home / Industry News

Read news issued by STV Valve Company and acquire more comprehensive information about Company, latest valves and valve industry progress

Face to Face Dimensions of Flanged Valves ASME B16.10

/in /by

What is the face to face dimension of a flanged ball, globe or gate valve? The ASME B16.10 chart answers this question, as it standardizes the distance between the inlet and the outlet of the most common flanged valves. The purpose of this ASME specification is to ensure the interchangeability of valves produced by different manufacturers.

Notes:

  • (1) Globe and horizontal lift check only.
    The face-to-face and end-to-end dimension for Class 150 steel flanged swing check valves in NPS 5 is 330 and in NPS 6 is 356.
  • (2) Globe and horizontal lift check only.
    The face-to-face and end-to-end dimension for Class 150 steel flanged swing check valves in NPS 16 is 864.
  • (3) Swing check only.

General notes:

  • Dimensions are in millimeters unless otherwise indicated.
  • The face-to-face dimension for flanged Valves is the distance between the extreme ends which are the gasket contact surfaces.
  • End-to-End dimensions apply to flanged Valves where the gasket contact surfaces are not located at the extreme ends of the Valve. The distance between the extreme ends is described as the end-to-end dimension and applies to flanged Valves like: Ring Joint, large or small female and large or small groove.

ASTM material specifications for valves

/in /by

Learn about the key ASTM material specifications for valves. A cast valve body is manufactured by pouring liquid metals into molds and is common for valves above 2 inches in diameter. A forged valve body is produced by forging and machining solid steel. The key specifications for cast steel valves body materials are ASTM A216 (WCA, WCB, WCC), ASTM A352 LCB/LCC (low-temperature), and ASTM A351 CF8/CF8M. ASTM A105, A350 and A182 cover body materials for small size (or high pressure) forged valves.

CAST STEEL VALVES

1505908241-7177-Valvebody

First, let’s clarify the difference between cast vs. forged valve, even if it may seem obvious: cast valves feature a cast body, forged valves have a forged body. That’s it! The difference relates to the valve body material construction technique, i.e. steel forging or casting.

Let’s now review the key cast valve body materials.

ASTM A216 WCA, WCB, WCC (CARBON STEEL HIGH-TEMP.)

The ASTM A216 specification covers 3 grades of carbon steel (WCA, WCB, and WCC), which feature slight differences in terms of chemical and mechanical properties. These grades for cast valves bodies match carbon steel pipes in grades A53, A106, API 5L.

ASTM A216 steel castings shall be heat treated and can be manufactured in the annealed, or normalized, or normalized and tempered conditions. The surface of steel castings shall be free of adhering elements such as sand, cracks, hot tears, and other defects.

ASTM A216 carbon steel valves (cast), material chart
ASTM A216 GRADE C Mn P S Si Cu Ni Cr Mo V
WCA UNS J02502 0.25(1) 0.70(1) 0.04 0.045 0.60 0.30 0.50 0.50 0.20 1.00
WCB UNS J03002 0.30(2) 1.00(2) 0.04 0.045 0.60 0.30 0.50 0.50 0.20 1.00
WCC UNS J02503 0.25(3) 1.20(3) 0.04 0.045 0.60 0.30 0.50 0.50 0.20 1.00

Notes:

  1. For each reduction of 0.01% below the specified maximum Carbon content, an increase of 0.04% manganese above the specified maximum is allowed up to a maximum of 1.10%.
  2. For each reduction of 0.01% below the specified maximum Carbon content, an increase of 0.04% Mn above the specified maximum is allowed up to a maximum of 1.28%.
  3. For each reduction of 0.01% below the specified maximum Carbon content, an increase of 0.04% manganese above the specified maximum is allowed to a maximum of 1.40%.

ASTM A352 LCB/LCC (CARBON STEEL LOW-TEMP.)

The ASTM A352 specification covers multiple grades of low-temperature carbon steel (called LCA, LCB, LCC, LC1, LC2, LC3, LC4, LC9, CA6NM) for cast steel valves, flanges, fittings, and other pressure-containing parts.

Chemical composition of A352 cast valves Gr. LCA/LCB/LCC (valve material chart):

GRADE C Si Mn Cr Mo Ni Cu Nb V
ASTM A352 LC3 0.15 0.6 0.65 3.5
ASTM A352 LCA 0.25 0.6 0.7 0.5 0.2 0.5 0.3 0.03
ASTM A352 LCB 0.3 0.6 1 0.5 0.2 0.5 0.3 0.03
ASTM A352 LCC 0.25 0.6 1.2 0.5 0.2 0.5 0.03

ASTM A351 CF8/CF8M (STAINLESS STEEL)

The ASTM A351 specification covers austenitic steel castings for valves, flanges, fittings, and other pressure-containing parts.

The most common grades are ASTM A351 CF3, CF8 (SS304), and CF8M (SS316).

The steel shall be made by the electric furnace process with or without separate refining such as argon-oxygen decarburization.

Any ASTM A351 cast part shall receive heat treatment followed by a quench in water or rapid cooling. The steel shall conform to the chemical and mechanical requirements set by the specification.

ASTM A351 stainless steel valves, chemical composition

Gate Valve Dimensions

/in /by

The tables show the dimensions and weights of API 600 gate valves (bolted bonnet / rising stem)

CLASS 150LB-2500LB

Dimensions in inches (millimeters)

 


 

 

 

 

Gate valve parts
Gate valve diagram showing the key parts of a gate valve for piping

WEDGE TYPES

The image below shows how the gate valve wedge opens and closes the flow of the fluid by application of a vertical movement (which can be manual or operated by an actuator).

Gate valves open and close function
The wedge is positioned between two parallel (or oblique) seats which are perpendicular to the flow. The fluid flows horizontally through gate valves and is not subject to pressure drops. Wedges can be of different types:

  • “solid-wedge” (in this case, the wedge is manufactured with a solid piece of steel)
  • “flexible-wedge” (in this case the disc features cuts around its perimeter to enhance the ability of the valve to correct changes in the angle between the seats)
  • “split-wedge” (two pieces construction disc, to enforce self-alignment of the wedge on the seats)
  • “parallel-slide wedge“

Wedge types for gate valves

STEM TYPES

A gate valve may have a rising stem (in this case, the stem rises above the handwheel if the valve is opened) or a non-rising stem (the stem doesn’t move above the valve when it is opened).

Rising and non rising stem of gate valves

GATE VALVE DIAGRAM

The gate valve diagram shows the standard assembly drawing of a gate valve. Many design variations are possible, depending on the gate valve parts configuration:

  • body material construction: forged or cast
  • bonnet design and connection: can be standard or pressure seal (high-pressure gate valves), bolted/welded bonnet, etc.
  • ends connection: gate valves are available with multiple valves ends designs (socket weld and threaded for forged gate valves and butt weld for cast body gate valves)
  • wedge type (solid/flexible/split/parallel slide): see details below in this article
  • stem type (rising/ non-rising): see details below
  • manufacturing norm: API vs EN gate valves have slightly different designs
  • type of valve operation: manual, gear or pneumatic/hydraulic/electric actuation
  • etc.

OS&Y VS. IS&Y DESIGN

It is very frequent to see the term “OS&Y” associated with gate valves.
This term means that when the handle of a gate valve is rotated to open or close the valve, it directly raises and lowers the disc by interacting with the stem of the valve.

In an “OS&Y gate valve”, the stem of the valve itself raises and lowers outside the body of the valve in a very visible way, while the handle remains in a fixed position.

When the stem raises, the disc inside the body of the valve rises from the seat letting the fluid flow through the valve (valve in open position).
Therefore with an OS&Y gate valve, the actual position of a valve (closed or open) is always evident to the operators.

Differently, the valve position is not immediately visible for “IS&Y gate valves” (inside screw and yoke), as the stem of the valve does not raise or lowers outside the valve when the handle is rotated.

How to Select Gate Valve Materials

/in /by

The material selection of gate valve mainly depends on the fluid medium and working environment. According to the different medium and environment, the material selection is also different. Generally speaking, the material selection of valve is divided into three aspects; the sealing surface of valve disc, in which the valve body is generally made of carbon steel cast iron (gray cast iron ductile iron) stainless steel (304 316) and the valve plate is made of carbon steel stainless steel (304 316) dual phase steel (2507 316) Generally, the sealing surface of nylon coating lining fluorine has: NBR EPDM PDEF ppl. Customers can choose the corresponding material according to their actual needs. Please contact our sales staff and look forward to cooperating with you.

BODY

The body of gate valves below 2 inches is generally made of forged steel (the most common body material grades are ASTM A105 for high-temperature service, ASTM A350 for low-temperature service and, ASTM A182 F304/F316 for corrosive service).
The bodies of gate valves of bore sizes above 2 inches are, instead, made of cast steel (the main cast grades are ASTM A216 WCB for high-temperature service, ASTM A351 for low-temperature conditions and ASTM A351 CF8 and CF8M – i.e. stainless steel 304 and 316 gate valves).

TRIM

The removable and replaceable parts of the valve are collectively defined as “trim” (for a gate valve: seat, disc, backseat and, stem).
The API 600 specification foresees a number of standard trim combinations, as illustrated below

API TRIM # BASE MATERIAL MATERIAL FOR SEAT MATERIAL FOR DISC BACKSEAT
MATERIAL		 MATERIAL FOR STEM
1 410 410 410 410 410
2 304 304 304 304 304
3 F310 310 310 310 310
4 Hard 410 Hard 410 410 410 410
5 Hardfaced Stellite Stellite 410 410
5A Hardfaced Ni-Cr Ni-Cr 410 410
6 410 and Cu-Ni Cu-Ni Cu-Ni 410 410
7 410 and Hard 410 Hard 410 Hard 410 410 410
8 410 and Hardfaced Stellite 410 410 410
8A 410 and Hardfaced Ni-Cr 410 410 410
9 Monel Monel Monel Monel Monel
10 316 316 316 316 316
11 Monel Stellite Monel Monel Monel
12 316 and Hardfaced Stellite 316 316 316
13 Alloy 20 Alloy 20 Alloy 20 Alloy 20 Alloy 20
14 Alloy 20 and Hardfaced Stellite Alloy 20 Alloy 20 Alloy 20
15 304 and Hardfaced Stellite Stellite 304 304
16 316 and Hardfaced Stellite Stellite 316 316
17 347 and Hardfaced Stellite Stellite 347 347
18 Alloy 20 and Hardfaced Stellite Stellite Alloy 20 Alloy 20

MATERIAL SELECTION

TRIM RECOMMENDED SERVICE
13% Cr, Type 410 Stainless Steel For oil and oil vapors and general services with heat treated seats and wedges.
13% Cr, Type 410 plus Hardfacing Universal trim for general service requiring long service life up to 1100°F (593°C).*
Type 316 Stainless For liquids and gases which are corrosive to 410 Stainless Steel, up to 1000°F (537°C).*
Monel For corrosive service to 842°F (450°C) such as acids, alkalies, salt solutions, etc.
Alloy 20 For corrosive service such as hot acids -49°F to 608oF (-45°C to 320°C).
NACE Specially treated 316 or 410 trim combined optionally with B7M Bolts and
2HM nuts to meet NACE MR-01-75 requirements.
Full Stellite Full hard faced trim, suitable for abrasive & severe services up to 1200°F (650°C).

What is a ball valve?

/in /by

What is a ball valve? It’s a question new customers often ask us at sales team, so let’s look into this to answer the question and explain what a ball valve is.

A ball valve is described as a mechanical device that directs, guides and modulates the flow of various types of liquids by way of an opening of a ball which has an opening in the middle. The opening is referred to as the port. By turning the handle on the ball valve, this manually opens/closes the port which controls the pressure from the flow of the liquid. Durability and “perfect” shutdown/shutoff are what makes the ball valve advantageous over other type of valves.

Valves are found in our everyday living and may go unnoticed. For example, there are plumbing valves which are at our sinks in our spigots. There are valves inside our washing machines, dishwashers, gas fireplaces, outside water spigots, refrigerators and more. Various types of industries utilize valves for their productions. Such industries include electronics, power, automotive, printing, plastics, textiles, metal, medical, chemical and food, to name a few. The industries that utilize ball valves typically have a need for supporting high pressure and temps exceeding 480 degrees. Ball valves are simplistic to operate and repairs are made easily without being removed from their pipeline.

Being made of steel, brass, iron, bronze or PVC, ball valves can range in sizes from .2 to 11.81 inches. More complex control systems using valves that need to regulate flow through a pipe will need an actuator. The actuator controls the valve pneumatically or is motor-operated and keeps it positioned appropriately so that the flow of the liquid is precise to the changing pressures and flow levels.

The basic types of ball valves include Full Port, Reduced Port, V-port, Multi-port, Standard Port and Cavity Filler ball valve. There are 3-way and 4-way ball valves. Depending on the application would determine the type of ball valve being used. The specifications to be considered for determining the appropriate ball valve would be the temperatures and pressure, number of ports, valve size, type of body material, end connectors and configurations.

 

FAQ

What is a ball valve?

A ball valve is a shutoff valve that controls the flow of a liquid or gas by means of a rotary ball having a bore. They can operated by a handle or automated with an electric or pneumatic actuator.

Is there a ball valve installation guide?

Screw on the input and output of the ball valve into your threaded assembly. Ensure the handle is installed correctly (parallel is open) before installation.

Can ball valves fail?

Yes, a ball valve can fail. Common failure types are a damaged seal (valve won’t seal 100%) or debris entered the valve (valve won’t move).

How Does A Knife Gate Valve Work

/in /by

A knife gate valve is a component that utilizes a blade to cut through clogging of heavy liquids. These valves were designed to work in some of the most corrosive, erosive and abrasive environments in the world.

Knife gate valves were originally designed for the pulp and paper industry. Stringy pulp would get stuck between the wedge and the seat of a normal gate valve and prevent flow shut-off. Knife gate valves were specially designed with a sharp edge to cut through the pulp and seal.

How a Knife Gate Valve Works
Because of this highly effective design characteristics, knife gate valves have become invaluable when it comes to applications that involve viscous fluids, slurry and other systems where impingement is an issue.

Knife gate valves are used is a lot of processing plants today and come in large sizes which make it easier to handle thick flows of light grease, heavy oils, varnish, slurry, waste water and paper pulp. It’s important to note that these valves do have low-pressure limitations and are designed to seat the blade into an elastomer seal once the blade cuts through the substances its handling. Thick liquids easily glide over these soft seals with no interference, however, when a solid mass or powder passes through the knife gate, the bulky, dry material ends up packing into the soft seals located at the end of the gate. When this happens, the seals eventually won’t close tightly enough. If this happens the seals will need to be replace.

When not to Use Knife Gate Valves
These valves shouldn’t be used to regulate flow because whenever fluid is forced against a partially closed gate, a vibration takes place, gradually eroding the disk and seat. Consequently, knife gate valves should only be used completely closed or opened. In addition, these valves are designed to slowly open and close to safeguard against the impacts of water hammer.

Knife Gate Value vs. a Gate Valve
The biggest difference between knife gate valves and gate values is that gate valves are manufactured to ANSI standards while knife gate valves comply with TAPPI standards. The gate valve is also flanged, wider dimensionally, ANSI pressure rated and its API leak tightness standards need to be met. Gate values are bi-directional, and widely used in fluid applications and they only come with metal seats. Another difference between a knife gate valve and an ANSI gate valve is within the packing gland area. A gate valve has a v-ring packing set that seals the shaft that is attached to the gate. Knife gate valves have a packing gland area that seals around the gate.

A knife gate valve has a thin profile in comparison to an ANSI gate valve. Knife gate valves are predominately uni-directional (some options are bi-directional) and feature a lugged or wafer body, without flanges. The knife gate valve seats are available in everything from resilient to the metal versions.

The most significant benefits of knife gate valves are the weight (16″ usually less than 300#) and the cost. ANSI gate valves are usually over 1200# and they more expensive.

What Is A Butterfly Valve?

/in /by

A butterfly valve is a regulating and shut-off device that can be an alternative, in some applications, with globe valve and ball valves.

This type of valve may be classified base on multiple parameters:

design: centric, double eccentric, triple eccentric
end connection type: wafer, lug (semi or full), flanged and double flanged
seat material: soft (example: Teflon, Buna, rubber, etc) or metal-to-metal (SS304, SS316)
body and disc materials (from cast iron to high nickel alloys)
actuation: manual (lever, gear, a worm gear) and actuated (electric, pneumatic, hydraulic and gas-over-oil types

A butterfly valve is used to shut off or modulate the flow of a fluid (isolation and regulation). API 609 Centric butterfly valves (soft seated) are preferred to gate and ball valves for low-pressure and non-critical applications as they are cheaper, lighter and easier to install. Eccentric butterfly valves (double offset and triple offset valves) with metal seats have surged in popularity and compete with globe and ball valves for some applications.

 

 

 

What Is The 2205 Material

/in /by

Duplex stainless steel (UNS S31803, S32205, S32750, S32900) combines the advantages of Ferrite and Austenite steel. Its duplex structure is conducive to obtaining high strength and stress resistance. In addition, higher content of chromium, nitrogen and molybdenum increases corrosion performance and duplex steel also has good welding performance. Due to its excellent properties, duplex stainless steel is widely used in chemical industry, paper manufacturing, desalination equipment, firewalls, Bridges, pressure vessels, heat exchangers, turbine blades and transmission shafts of offshore systems.

Sometimes, UNS S31803 and UNS S32205 are referred to as duplex 2205. Generally, UNS2205 contains ASTM S31803 and S32205 duplex stainless steels. In other words, S31803 and S32205 are both called 2205 stainless steel, and S32205 is the upgraded series of S31803 by the adding of the lower limit content of Cr, Mo and N elements, which makes the little difference in mechanical properties. Their tiny differences in chemical elements and physical properties are showed below:

UNS2205 C max P S Si max Mn max N Mo Ni Cr
S31803  0.03  0.03 0.02 1.00  2.00 0.08-0.2 2.5-3.5 4.5-6.5 21.0-23.0
S32205  0.03max 0.03 0.02 1.00max 2.00 max 0.14-0.2 3.0-3.5 4.5-6.5 22.0-23.0
UNS2205 Tensile strengthmin, Mpa Yield strength0.2% offset, min, Mpa Elongation, A5%
S31803 620 450 25
S32205 655 450 25

According to the ASTM A182 Standard, Specification for forged or stainless steel pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service, UNS S31803 and UNS S32205 cannot be confused and they specified in different number, S31803 is marked by F51 and S32205 is F60.

When speaking of 2205 steel, it generally refers to S31803 or F51, while UNS S32205 or F60 conforms to ASTM 2205 adopts its higher corrosion resistance range, that is, UNS S32205 requires higher Chromium and Nitrogen content, thus guaranteeing better corrosion resistance. Generally, S32205 steel plate and S31803 are also called double standard steel plate, or 2205 steel plate for short. Our factory produce 2205 tubing and 2205 plates to make its chemical composition conform to two specifications of UNS 31803 and S30025. Our steel plate in stock can meet two kinds of standards at the same time.

 

 

Mechanical properties of 2205 duplex

2205 (UNS S32305) is a nitrogen-alloyed duplex stainless steel, with a chemical composition containing 22-23% chromium, 3-3.5% molybdenum, and 4.5-6.5% nickel.   The high chromium and molybdenum content provide good corrosion resistance, and the overall combination allows this alloy to be stronger and tougher than most standard austenitic steels. 2205 duplex stainless steels maintains good weldability in their thickest sections, and they are much more resistant to chloride stress corrosion cracking and pitting than standard austenitic steels like 316L or 317L. 

With nearly twice the yield strength of other comparable austenitic grades, 2205 duplex steel products can withstand higher pressures and more corrosive environments with less material, saving on weight and fabrication costs.  This makes them ideal for chemical processing and storage pressure vessels and tanks, or high chloride environments for marine applications.

United Performance Metals stocks 2205 duplex stainless steel plate in thicknesses from 0.125″ to 1.000″, with FirstCut+ Processing services available. 

Heat Treatment and Heat Resistance

Similar to other duplex stainless steels, this grade of material can suffer from hydrogen embrittlement at temperatures over 300C.  To solve this issue, 2205 duplex steel plate should be solution annealed at 1900°F (1038°C) minimum up to 2012°F (1100°C), followed by a water quenching for rapid cooling. While it can be work hardened, thermal treatments will not harden this grade of stainless steel.

Machining and Weldability

The high strength of duplex 2205 makes it difficult to machine. Strong, rigid machines with low vibration are recommended, and carbide tooling will require lower feed speeds. 2205 plate is easily welded, but care should be taken to use appropriate filler materials (such as 2209, which is over-alloyed with additional nickel) to prevent excess ferrite formation.

STV Delivery ANSI 150LB Gate Valve to Customer of South American

/in , /by

STV Delivery ANSI 150LB Gate Valve to Customer of South American

150LB 1.- CLASS 150
2.- Valve design: API 600 / ASME B16.34
3.- Body: Carbon steel: ASTM A216-WCB
4.- Bonnete: ASTM A216-WCB
5.- Gate: A216-WCM carbon steel / 13% carbon
6.- Seat: Forged Steel ASTM A-105 / Estellita (Coated)
7.- Stem: ASTM A182
8.- Rear seat: A276-420
9.- Gasket:  A.276-420        STEEL VALVE TYPE BRIDGE TYPE  CLASS 150		 14“ 3 RF
150LB 18” 4 RF
150LB 24″ 4 RF

What Is The Purpose And Maintenance Instructions Of A Sight Glass?

/in /by

The purpose of a sight glass is to allow plant managers and engineers to look inside of their systems without disrupting the environment within. Often referred to as viewing glasses, they offer you a way to see the levels of liquids or gases that are traveling through a critical point of your design, monitor pressure changes, and virtually anything else that sight glass windows could allow you to do. With their widespread use, sight glasses have become critical to operations such as steam pipelines, chemical processing, pharmaceutical processing, and food processing.

The pipeline sight glass is one of the main accessories on the industrial pipeline device. It can observe the flow reaction of gas, liquid, steam and other media in the pipe at any time, monitor the production, and avoid accidents in the production process. Often used in chemical, chemical fiber, petroleum, pharmaceutical and other production pipelines

Repair and maintenance of pipe mirror

  1. The Sight Glass is used to observe the flow of gas, liquid, steam and other media reaction equipment, its window glass should be kept clean without dust;
  2. The Sight Glass of the mirror belongs to the appropriate damaged part, which should be handled with care when installing the mirror;
  3. There are some limitations in the temperature and pressure resistance of Sight Glass
[nolink]