What Is an Isolation Valve?
An isolation valve is designed to distinguish one part of your drainage system from the rest so that water can’t flow through it. It is mainly used when you need to fix a plumbing problem but don’t want to turn off the water to the rest of your house. When you turn off the isolation valve, the water supply to the isolated part stops. This helps repairs be done without stopping the water supply to the rest of the house. Most of the time, isolation valves are used when a plumbing problem is only in one area, like a sink in the bathroom or kitchen.
What is a Gate Valve?
A gate valve is a control valve that permits unrestricted media passage or stops the fluid flow. The primary advantage of a gate valve is its obstruction-free passage. This may result in minimal pressure loss over the valve. Unlike butterfly valves, the open bore of a gate valve allows for the passage of flow during the pipe-cleaning process. However, because gate valves are slower than quarter-turn valves, they should only be used in the fully open or closed position.
Why Is Isolation Valve Used?
An isolation valve allows for the controlled stopping and redirecting of process media. It aids in the shutdown of process plants when vent pipes or drain lines are installed. During regular operation, these controls are in the open position. Shut when necessary for safety or routine maintenance and repairs to the system. Installing isolation valves at the blank end of a line or manifold facilitates the insertion of additional parts without stopping regular operations.
Why Gate Valve Is Used?
In addition to redirecting water flow throughout the conduit, gate valves isolate specific sections of the water distribution system during maintenance, repairs, and new installations.
Since innovative valves have become increasingly popular, they may not be used as frequently as they once were, but gate valves are ideal for specific applications. Irrigation applications continue to utilize gate valves because gate valves continue to offer significant benefits to the industry.
Isolation Valve Vs. Gate Valve: Structure
Isolation valves feature two or more ports. Further, it offers tight sealing and leakage for a metal-seated isolating valve. Isolating valves require more space to install a quarter-turn handle.
The gate valve features two ports at the most. It’s prone to leaks compared to isolating valves. Gate valves require less space to install a shut-off handle.
- Isolation Valve Vs. Gate Valve: Parts
Parts of The Isolation Valve
The isolation valve consists of these components as shown in the figure above:
- Valve seat
- Valve disc
- Body of valve
- Bonnet
- Stem seal
Parts of The Gate Valve:
Every component of a gate valve is responsible for its effective operation. Let us now look at the components of the gate valves that make up its structure.
Gate: gate functions by assuring high-quality leak sealing. The majority of gates are wedge or similar in shape. A knife-style gate is another example. These gates allow ample room for fluids to flow. They prevent liquid when closed by twisting the wheel. Diverse gate structures have diverse purposes.
Stem:
Stem is essential to the operation of the gate valve. It includes a threaded system. By lifting the stem, we may lower the gate valve. A manual wheel can assist in relocating the stem. A stem might be ascending or not rising. Rising stems are ideal for handling by hand. The non-rising stem is ideal for use with underground equipment.
Bonnets:
The bonnets in a gate valve are in charge of preventing leaks. If the bonnets become faulty, we may remove and replace them. They come in several varieties.
Screw-in bonnets are standard and have a fundamental construction. In relatively tiny valves, they create leak-proof constructions. We employ bolted bonnets for high-pressure sealing in oversized valves.
Some gate valves require regular upkeep. Union bonnets are ideal for this purpose. They have a union nut that maintains the bonnet in place. It maintains bonnet quality when frequently removed for examination.
Seat: another critical component of gate valves is the seat. The seat can be either stem-mounted or ring-mounted. Seat rings make it easier to sit in high-temperature settings. Wedge-type gate valves feature primarily metal seats. There are also resilient seats, which are ideal for tight closures.
How Do Isolation Valves Work?
I explained above what isolation valves do, but how do they work? Water flows through them during regular operation. Yet, they are in the open or “on” position, as indicated on the isolation valve. When the valve is closed or ‘off,’ it will have a moving part, typically a screw or lever, that rotates at 90 degrees to the flow to shut off the water supply.
When the lever is aligned to the pipes or valve, it is open; when it is 90 degrees, it is closed. The screw head linking is one of the most prevalent forms of isolation valve. When the valve is open, the screw head lies in the direction of the valve or conduit, indicating the valve is open. It takes a quarter-turn of the screw to close the valve.
How Does Gate Valve Work?
There are a variety of structural and operational gate valve options. However, the way they work is consistent across all types. It employs a simple method of working.
The brass gate valve comes with hand wheels. To close the valve, turn it clockwise until it stops rotating. It will result in lowering the stem at the seat along the valve. Now, the opening is stopped. No liquid should be streaming across the valve. To prevent the gate valve from tearing, avoid applying excessive force when closing it.
Now, the opposite procedure applies to the valve’s opening. The direction of rotation for the hand wheel is counter-clockwise. Remember not to apply pressure, as excessive force can cause internal damage to the gate valve.
While controlling the valve, the user should observe typical safety measures. As most errors occur during opening and closing, it may assist in increasing longevity. If you recognize pressure while controlling the valve, you can loosen the screw on top of the body. It reduces pressure levels. In addition, it protects the stem and disc from injury. However, once the nut is free, you should return it to its original position.
In general, gate valves function as shut-off valves that can be completely open or closed. Therefore, it is not desirable to maintain them in semi-open positions. The water passage through the gate valve has maximal space based on minimal pressure. The semi-open function can operate in the case of throttling. On the other hand, this leads to fluids to flow back. This backflow diminishes the rating of the valve. Thus, it is preferred to avoid this situation.
Isolation Valve Functionality
If you need to do maintenance or repairs on a particular section of a pipeline, you’ll need an isolation valve. Both of its entrances are parallel to one another, making them ideal for the oil and gas industry. When an isolation valve is closed, it blocks the water flow from both directions. The use of hot forged steel ensures its durability and durability.
Gate Valve Design Functionality
To control fluid flow, a gate valve lifts an internal gate. They open and close at right angles to each other, making them perfect for use in on/off conditions. They have several applications, especially in the plumbing and water treatment sectors. When purchasing a gate valve, you may choose between rising stem gate valves and non-rising stem gate valves. They’re employed in high-pressure and high-temperature applications but require high maintenance. Homeowners choose non-rising stem gate valves because they require less maintenance.
Isolation Valve Vs. Gate Valve: Working Condition
The isolation valve withstands pressure up to 10 bar (145) with a working temperature range of -20°C to 180°C (-4°F to 356°F). On the other side, brass gate valves operate with media temperatures ranging from -20°C to 120°C and pressures ranging from 0 to 16 bar. However, bronze gate valves are typically used for water pipes and equipment conduits with pressures of 300 psi (20 bar) or less and temperatures between -20° C and 150° C.
- Isolation Valve Vs. Gate Valve: Size
Gate valve size:
| Size | Pressure |
| 1/2″ (DN 15) | 16bar/232psi |
| 3/4″ (DN 20) | 16bar/232psi |
| 1″ (DN 25) | 16bar/232psi |
| 1″1/4 (DN 32) | 16bar/232psi |
| 1″1/2 (DN 40) | 16bar/232psi |
| 2″ (DN 50) | 16bar/232psi |
| 2″1/2 (DN 65) | 16bar/232psi |
| 3″ (DN 80) | 16bar/232psi |
- Isolation Valve Vs Gate Valve: Maintenance and Repairs
Regular maintenance is vital for the accurate operation of isolation valves. Maintaining reliability requires regular inspection and testing. Inspecting isolation valves for leaks and corrosion is essential, which can lead to costly repairs if not treated quickly.
In contrast, gate valves require little maintenance but might become problematic if they aren’t used regularly. This is due to the thread in the stem becoming stuck after being unused for an extended period.
- Isolation Valve Vs. Gate Valve: Applications
Applications of Isolation Valve
Isolation ball valves find usage anywhere on/off switching is necessary.
- Isolation valves have evolved to meet a wide variety of uses and circumstances in a variety of industries. A further category is possible based on the closure device’s or obturator’s working motion:
- Linear motion valve: the obturator in linear-motion valves moves in a straight line. An actuated globe valve is also part of the ensemble. They are based on the earliest sluice gate designs used to control water flow in irrigation canals. Its versatility in flow applications has led to the development of several types since the start.
- When a linear motion valve opens and closes, the obturator moves in a straight line while the fluid flow is at an angle. Furthermore, these valves provide a secure seal via a threaded stem and obturator.
- Isolation valves have evolved to meet a wide variety of uses and circumstances in a variety of industries. Further types are based on the closure device’s or obturator’s working motion:
- Linear motion valve: the obturator in linear-motion valves moves in a straight line. An actuated globe valve is also part of the ensemble. They are based on the earliest sluice gate designs used to control water flow in irrigation canals. Its versatility in flow applications has led to the development of several types since the start.
- When a linear motion valve opens and closes, the obturator moves in a straight line while the fluid flow is at an angle. Furthermore, these valves provide a secure seal via a threaded stem and obturator.
Rotatory motion valves These valves with a rotary motion have an obturator that rotates around an axis perpendicular to the flow direction. Steam applications make use of the two most prevalent and vital rotatory valves.
Gate Valve Applications
There are numerous industrial and residential applications for gate valves.
• slurries: gate valves are frequently used in applications where slurries serve as the medium. Because a gate valve has an unobstructed fluid passageway, the slurry can readily pass through the valve. Additionally, knife gate valves can effortlessly cut through sediment to close.
• viscous media: gate valves are typically employed for viscous media such as light lubricants and oils. The unobstructed passageway facilitates the free movement of these media. The valve can be pigged, a standard method for cleaning in these applications. In addition, valves for these uses are typically open or closed for extended durations.
• water gate valves: since flow control is typically not required for water applications, water gate valves are commonly utilized. The valve can be completely open or closed, enabling water regulation.
Isolation Valve Vs. Gate Valve: Other Differences
- Isolation valves separate a portion of conduit or equipment from the remainder of the system.
- Gate valves are used to regulate the fluid passage within a conduit.
- Isolation valves are typically installed in systems where it is necessary to isolate a section of piping for maintenance or repair.
- Gate valves are typically installed in systems where the capacity to regulate fluid passage through a conduit is essential.
- Isolation valves are offered in brass and plastics, among other materials.
- Gate valves are available in brass, bronze, stainless steel, etc.
- Isolation valves are typically manually operated, whereas gate valves can be operated manually or automatically.
- Typically, gate valves are installed upstream of isolation valves to offer more control over the system.
Isolation Valve Vs. Gate Valve: Which One Is Better?
Gate valves are preferable to isolation valves due to their numerous advantages. Their primary advantages are their low-pressure drop, ideal flow capacity, and robust shut-off capabilities. When fully opened, gate valves provide a straight-through passageway for low flow resistance and high flow rates. This function is particularly beneficial in systems where maintaining constant pressure is essential.
In addition, gate valves are well-known for producing a secure seal when closed, stopping leaks. These characteristics make gate valves suitable for on/off applications requiring reliable separation without compromise. Gate valves excel in circumstances needing immediate shut-off, rapid and complete flow cessation, or environments with vibration issues due to their versatility.
Isolation Valve Vs. Gate Valve: FAQS
Can Gate Valves Be Utilized at The Line’s End?
Gate valves are not recommended for use at the end of a pipeline (end of line duty) due to their inability to withstand the increased pressure and flow conditions that may exist at the end of a pipeline.
Do Isolation Valves Need to Be Open or Closed?
In daily use, these valves are typically left open so that the user can control the water flow rate, for instance, by turning on and off a faucet. Nonetheless, if this faucet needs to be replaced, the isolation valves are closed so that no water flows when the faucet is removed.
What We Solve in this Article?
In conclusion, isolation and gate valves function differently and are designed to suit distinct needs. While isolation valves are optimal for applications requiring a complete flow shut-off, gate valves are suitable for applications requiring moderate to high flow rates. Understanding the distinctions between isolation and gate valves is crucial when selecting the appropriate valve for a given application. In addition, complete inspection and upkeep of these valves may assist in improving the lifespan and prevent damage.