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Instrument Valves and Accessories are a critical part of any Instrument Hook Up. The valves and accessories include those listed below. Should you have a question on or need to purchase quality Instrument Valves and Accessories our Sponsors Prochem Pipeline Products are Experts in this area! Contact them here.
Go to Specific Subject: Common Questions Associated with Instrument Valves and Accessories | Instrument Ball Valves | Instrument Bleed Valves | Instrument Check Valves | Close Coupled Mono flange and Large Bore Direct Mount Manifold | Primary Isolation Double Block and Bleed Valves | Instrument Excess Flow Valves | Instrument Gauge Valves | Instrument Hand and Gauge Valves | Micron Filters | Instrument Needle Valves | Instrument Relief Valves | Instrument Root Valves | Instrument Toggle Valves | Instrument Tubing Saddles | Instrument Enclosures, Sunshades and Supports | Checking for Instrument Gas Leaks | Other Useful Information on Instrument Valves and Accessories |
What does NPTF thread stand for?|
NPT thread stands for National Pipe Taper. It refers to the thread that tapers inward to create a better seal. It is recommended that care is taken in regards to the thread tolerances and only the best quality units are purchased to achieve this. It is imperative that any manufacturer has demonstrated quality assurance to a high standard. It is worthwhile ensuring the quality of threads by gauging at least a proportion of the threads to ensure compliance. Also it is recommended that thread tolerances and gauging should be specified to a tolerance better than the requirements of ASME B1.20.1. ICEweb's compression fittings page has a more detailed explanation of the gauging and tolerance requirements.
What is an OS&Y valve?
An OS&Y valve is an Outside Screw and Yoke valve. It is a part of the piping specification. It has a firesafe outside screw construction.
Why is the Molybdenum content of 316SS 2% minimum in an offshore environment?
The molybdenum content is at a minimum 2% to prevent chloride corrosion.
Why is 303 or 304SS not to be used in an offshore environment?
303 or 304SS is not to be used because their molybdenum content is nil and thus the material is subjected to chloride corrosion.
Is there a maintenance issue when Close Coupled Monoflanges are used? If the Monoflange is installed on a clean, non blocking process then it is not an issue in that access to the tapping point is required very rarely. This is especially so on Fieldbus and HART systems as the transmitter provides a huge amount of diagnostics on-line. The huge advantage of Close Coupling is that many instrument fittings are no longer required, thus eliminating potential leak failure points.
Purpose Ball Valves at a Glance - Ball valves provide
a wide range of capabilities for various applications. Select a ball
or trunnion valve for simple operation, visual indication of flow, full
porting for maximum flow, rodability and long cycle life.
- Choose a 2-way ball valve for quick, quarter-turn, on - off service.
- A 3-way ball valve employs 180° operation for diverting flow from one line to another.
- 4-way valves are dual switching valves, changing two flow paths at the same time. 5-way, or diverter, valves allow flow through any of four possible paths.
High Cycle Ball Valves at a Glance - High Cycle ball valves are designed for repeatable, zero leakage sealing when control conditions demand valve actuation exceeding 50,000 cycles. Their unique stem- and seat designs provide packless-free operation and ease of maintenance.
Fire Safe Ball Valves - Fire Safe Valves meet demanding application requirements in the production environment of chemical and petrochemical processing facilities. These valves have been tested to and meet the requirements of API 607, 4th edition for soft seated valves. API 607 measures the ability of a closed soft-seated ball valve to retard the propagation of a fire (downstream and to atmosphere).
Instrument Bleed Valves - Bleed valves allow for quick, easy manual bleed-off of system pressure.
Instrument High Flow Poppet Check Valves - These Valves, recommended for severe service, including CNG applications have the following features, High Cv flow rates, Blowout-proof o-ring design, Ability to withstand high opening shocks without damage.
ICEweb's Monoflanges and Instrument Manifolds page has extensive technical engineering information on this subject.
Technical Reference on Primary Isolation Valves - This comprehensive Technical reference from Anderson and Greenwood gives excellent information on;
Primary Isolation Valve - Primary Isolation Valve applications, advantages and disadvantages, features and benefits, Quarter Turn Ball Valve specifications, OS&Y Needle Type Globe Valve Specifications, HD Needle Type Globe Valve Specifications, along with a comparison with more traditional valve hookups.
Double Block and Bleed Valves - These valves are integrally forged, one-piece double block and bleed assemblies for primary isolation of pressure take-offs, where the valve is directly mounted to the vessel or process pipe. Instruments may be directly mounted to the valve outlet or alternatively remotely mounted with gauge lines/impulse pipe work. .
Unique Series of Optional End Connections - This bulletin feature a unique series of really smart optional end connections which can be bolted onto the valve outlet in place of the standard 1/2-inch NPT female threaded connection. Bolt on connections are available as: Instrument Kidney Flange / Welded Connection / Dual Threaded Connection.
Enhanced Locking Security of Instrument Valves - Ball valve locking handle provides additional security against tampering or accidental loosening as a result of vibration or physical damage. Allows the valve to be locked open or closed.
Quill for chemical injection and
Monoflanges - also see ICEweb's Monoflange and Instrument Manifold page.
Root Valves - An integrally forged one-piece block and bleed assembly for primary isolation of pressure take-offs, where the valve is either screwed or welded directly into the vessel or process pipe without the need for a flanged connection. Instruments may be directly mounted to the valve outlet or alternatively remotely mounted with gauge lines/impulse pipe work.
Excess Flow Valves - These valves act as flow switches that automatically close when a flow spike occurs, preventing uncontrolled release of system fluid. They are available in automatic and manual reset versions, depending on system requirements. Automatic reset versions can have an “anti-clog” wire which increases reliability by preventing a build up of system fluid in the bleed port. Others are high pressure (0 to 6000 psig [414 bar]), high performance, quick acting, zero leakage, low maintenance excess flow valves that will help provide a reliable and safe working environment.
Technical Reference On Gauge Valves - This comprehensive Technical reference from our sponsor Prochem Pipeline products gives excellent information on;
Bonnet Technology - Covering both soft and hard seat, mini bonnet assembly, arctic low temperature applications.
Block and Bleed - Static pressure gauge and instrument installation for isolation and venting.
Multi-Port Gauge Valves - These valves allow the versatile positioning of gauges or pressure switches without requiring additional penetration of the main piping
OS&Y Root Valves-Root Isolation Valves with Outside Screw and Yoke, Bolted Bonnet Construction - This is a multi-ported OS&Y root/primary instrument isolation valve, designed for use with gauge mountings and other pressure instruments in refineries and chemical plants. It facilitates installation of multiple measurement devices without additional penetrations of the main piping.
Gauge Valve Accessories
- Bleed Tee- A Bleed Tee is a single male inlet, triple female outlet piping tee. It is generally used with the process root valve to simplify downstream piping and reduce the number of potential leak points. The Bleed Tee can be used with any 1/2-inch or 3/4-inch valve in an instrument piping system and allows either vertical or horizontal pressure gauge mounting. As an option, a bleed plug (as shown above) can be assembled into the tee to provide a means of relieving pressure for maintenance purposes.
- Bleed Plug - The bleed plug provides an economic means to bleed process pressure trapped between the Valve and instrument. This bleeder valve vents to atmosphere and has bubble-tight shutoff
- Seat Resurfacing Tool - The flow of abrasive fluids may, over time, score the seating surface of the valve body. The seat resurfacing tool will re-machine this surface and allow the valve to once again deliver bubble-tight shutoff.
- Bonnet Lock (patent protected) - The Bonnet Lock (BL) prevents accidental loosening of the bonnet-to-body seal, and is a low-cost alternative to a union bonnet. A high-strength short bonnet pin aligns a hex collar over the bonnet. A standard SS hollow-point set-screw or lock nut locks the collar against the bonnet. Tests indicate that the minimum torque required to break the collar loose is greater than the torque required to twist off the valve stem.
- Gauge Adapters - Designed for use with any gauge valve to increase site versatility, the GA swivel gauge adapter allows positioning of pressure gauges in any direction through 360 degrees via a compression fitting.
- Gauge Syphons - Designed to replace the old pigtail type of siphon, this accessory provides a thermal barrier between hot vapours and the pressure instrument. It reduces the amount of potential gauge whip on vibrating lines by bringing the gauge closer to the process connection.
Hand and Gauge Valves - These include multi-port and block and bleed styles suitable for gauge isolation, calibration and venting with a choice of either globe pattern or through-bore designs. A wide choice of end connections and comprehensive range of standard gauge accessories allows complete flexibility for individual installations - From our sponsor Prochem Pipeline products
Micron Filters - With a Variety of Micron Filtering ranges from 2 to 55μ these units have applications such as trapping foreign particles, protecting sensitive equipment, system purging and acting as a pressure damper, see page 27.
Needle Valves at a Glance - This technical bulletin covers a complete line of precision needle valves. Before making your valve selection, be sure to consider the system pressure, operating temperature, required flow and materials of construction. It also details the following;
Design of Stem packing - Provides superior sealing performance while reducing maintenance costs. Consisting of alternate wafers of TFE and metal spacers, stem leakage is virtually eliminated while the problems associated with TFE cold flow are minimized.
Choice of Stem Tip Options to Provide Greater Flexibility
- Blunt Vee-Point - The blunt vee-point stem tip provides full flow with only a few turns of the valve handle.
- Vee-Point - The vee-point stem tip is used to provide leak-tight shutoff in small orifice valves.
- Regulating - The regulating stem tip has a gradually tapered tip which allows for greater control of flow.
- Non-rotating Metal Stem Tip - A non-rotating stem tip is typically used in high cycle applications to extend the service life of the valve. Its purpose is to prevent galling in the seat and on the stem tip. As the valve is closed, the stem tip contacts the valve seat, and is driven straight into it without rotating.
- Vee-Point - The vee-point stem tip is used to provide leak-tight shutoff in small orifice valves.
- PCTFE - A PCTFE stem tip requires a lower seating torque than a metal stem tip. It will provide full flow through the valve with only a few handle turns. The PCTFE tip is replaceable and has a maximum temperature of +250° F (+121° C)
- Non-rotating PCTFE Stem Tip - A non-rotating PCTFE stem tip operates in the same fashion as the non-rotating metal stem tip but requires less seating torque.
Flow capacity of HOKE Needle Valves - The Cv factor is a flow coefficient expressing the rate of flow in gallons per minute of 60° F (16° C) water with a pressure drop of 1 psi across the valve. The flow is dependent on the inlet and outlet pressures, temperature, specific gravity and the Cv coefficient. Both liquid and gas calculations are detailed.
Severe Service Needle Valves - details on a valve for steam and other severe service applications.
Sour Gas Service Needle Valves.
Right Angle Instrument Relief Valves - These valves provide users with high accuracy and consistency of cracking and reseat pressures. Furthermore, narrow pressure ranges (cracking pressures) for each model can be factory pre-set according to customer specifications. PED certification and CE marking are standard for all models.
Root Valves - These valves are an integrally forged one-piece double block and bleed assembly for primary isolation of pressure take-offs where the valve is either screwed or welded directly into the vessel or process pipe without the need for a flanged connection. Instruments may be directly mounted to the valve outlet or alternatively remotely mounted with gauge lines/impulse pipe work.
Instrument Toggle Valves - Featuring a simple, reliable design concept, this low-maintenance valve is well suited for a wide variety of applications. The toggle handle provides easy on-off operation and visual indication of flow.
Complete Tubing Control with Stainless Steel Saddles - Features 316 Marine Grade Stainless Steel, Weather and Corrosion resistant, 18g reinforced rib for added strength for sizes up to and including 12.7mm (1/2”) and Manufactured to precision tube tolerances.
It is essential that Instrument Enclosures and Sunshades are considered where Instruments are subjected to a wide range of environmental factors which might impair the efficiency and operation of process instrumentation, such as extremes of temperature, the ingress of dirt, dust and moisture, corrosion, accidental damage and tampering. Options can include electrical or steam heating, ventilation or integral insulation for protection from the world’s climactic extremes, such as Siberia, where the temperature can fall as low as -76°F (-60°C), or Australia / Middle East, where it can reach in excess of 104°F (+40°C).
Enclosure systems are typically used to protect process instrument manifolds and transmitters, solenoid valves, general field instrumentation and remote chemical sealed instruments.
These types of enclosures can be used with a specific range of enclosure manifold systems which enable ease of instrument installation and provides external process and vent connections.
Instrument Enclosures, Sunshades and Supports - Maintaining the integrity of process measurement instrumentation, protection from the effects of the industrial and the natural environment, both on and offshore, is vital, this technical bulletin from Anderson and Greenwood and our sponsors Prochem Pipeline Products gives a good technical overview of what is required. The bulletin covers Purpose and Applications, Features and Benefits, Technical Specifications Enclosures, EM Manifold Needle Valve, EM Manifolds, Electrical Heating, Electrical Heating, Enclosure Mounting and Instrument Shades.
Modular Mounting System - The Modular Mounting System for instrument impulse line installations has been developed in conjunction with Shell International (SIPM) and has particular applications in the petrochemical and refining industries. You will have to scroll down this document to get to this article. From our sponsors Prochem Pipeline Products.
Checking for Fitting Leaks? - "Leak detective" has the answer.
Matching Valve Type to Function - A Tutorial in Valve Selection - Michael D Adkins - In selecting valves for instrumentation, the choices are many and varied. The choice depends mostly on the application the valve is to be used for. When selecting a valve for an instrumentation system, your choices may seem overwhelming. Just to name a few, there are ball valves, diaphragm and bellows valves, as well as check valves, excess flow valves, fine metering, gate, multiport, needle, plug, relief, rising plug and safety valves. Further, each of these valves comes in many sizes, configurations, materials of construction and actuation modes. To make the best choice, it is always good practice to ask the first question in valve selection: what do I want the valve to do? From www.processonline.com.au
Our sponsors PROCHEM PIPELINE PRODUCTS also have a further range of associated products and technical information - find it here.