When handling critical flow applications, keeping service fluids clean is essential. Industrial pipelines contain several components that are sensitive to sediments, semi-solids and suspended particles. These impurities can clog downstream valves and affect the performances of process pumps, regulators and metering devices. Even small amounts of impurities can contaminate service fluids and damage pipes, reducing the reliability and longevity of piping systems.

The Y-strainer is a practical and affordable solution for preventing these impurities from damaging downstream fluid system parts.

Y-strainers are indispensable devices for removing dirt and debris from service fluids. They have a compact design to ensure suspended and solid particles are removed from fluids to protect downstream flow control devices.

In this article, we explore:

• How Y-strainers work
• Different types and designs of Y-strainers
• Choosing the right Y-strainer for various fluid applications
• Materials for fabricating and sealing Y-strainers
• Installing and maintaining Y-strainers

Working principles of a Y-strainer

Y-strainers are named for their Y-shaped design. They have a body that houses a specially designed mesh screen that filters service fluids. Other strainers use wedged wire elements or perforated metal to filter particulates. The screening element has small openings that allow clean fluids to pass through.

Physical appearance of a Y-strainer

Fluid enters the Y-strainer through the inlet port, flowing under pressure past the screening element. As the fluid flows past the perforated metal, the mesh traps any particles, debris, suspended solids, and other foreign matter that is larger than the screening openings. Clean fluid exits the Y-strainer through the outlet port, which is connected to adjacent pipelines.

The Y-strainer traps all debris and unwanted matter within its body. This debris can easily be removed by opening the strainer cap. This allows you to clean the Y-strainer and replace damaged or worn-out screens. Some Y-strainers have blowout kits for removing contaminants faster without disassembling the entire unit. The blowout kit is also called a blowdown connection.

Y-strainers are essential for any fluid application where fluid cleanliness is critical. The cleanliness of service fluids affects the reliability and durability of mechanical systems in a piping system. Y-strainers can protect sensitive elements like diaphragm and solenoid valves. Debris blocks ports of a solenoid valve and prevents diaphragm valves from full seating, causing minute leakages around them.

Y-strainers are common in:

• Steam service pipelines
• Industrial heat exchangers
• Air and natural gas applications
• Power plants (around condensers and turbines)

Y-strainers are preferable for their compact designs. The Y-shape provides seamless fluid flow without significantly changing flow direction.

Y-strainer End Connection Types

Y-strainers are available in a variety of sizes and designs to meet the performance requirements of different pipelines. Here is a detailed look at the different connection types.

Flanged end connections

Flanged-end Y-strainers are designed in accordance with various industry standards, including ANSI specifications. Y-strainers in this category can feature raised or flat faces to fit into different pipe sizes and designs. When installing flanged-end Y-strainers, it is important to align the end connections and use fasteners (bolts and nuts) to secure the Y-strainers in place.

Flanged connections have a gasket to create a strong seal that prevents leakage. Flanged-end Y-strainers are commonly used in pipelines that handle hazardous fluids. These pipelines require highly effective pipe joints. The temperature limit for most flanged-end Y-strainers is around 350 degrees Fahrenheit. As the temperature rises, the fasteners and gaskets in the pipeline may become loose, increasing the likelihood of media leakage.

Welded end connection

Welded end connections are common in high-pressure, high-temperature systems with permanent joints. These connections are either butt or socket welded. Butt welds provide strong connections between Y-strainers and adjacent pipes. Socket welds are more popular with small pipelines that prioritize strict leakage integrity.

Threaded end connections

Threaded end-type Y-strainers are common in domestic and commercial piping systems. They are relatively inexpensive and easy to install. NPT threaded end connections are made from a variety of materials, including stainless steel, brass, bronze, cast iron, and carbon steel. These Y-strainers have varying pressure class ratings, making them suitable for multiple fluid applications.

Electric Solenoid Valves has a wide range of stainless steel, threaded end-type Y-strainers with NPT thread ports. These Y-strainers can withstand high pressure, up to 800 PSI. They also utilize Polytetrafluoroethylene (PTFE) seals to ensure they are leak-proof at varying process pressure and temperature ranges.

These leak-proof, stainless steel Y-strainers are compatible with a variety of chemical media, making them ideal for food processing systems, potable water pipelines, chemical processing facilities, and steam pipelines.

Y-Strainer Filter Sizing

Y-strainers can only perform their intended task if the screen is properly sized. Process engineers must evaluate various fluid characteristics to select the correct mesh size. Y-strainer sizing is defined using mesh size or microns.

• A micron is a unit of measurement (one-thousandth of a millimeter). Small micron dimensions mean the Y-strainer has very minute screen openings.
• Mesh size indicates the number of screen openings for every linear unit (usually inches). For example, a Y-strainer with a mesh size of 18 has 18 screen openings for each inch.

You can easily convert between microns and mesh sizes using a standard conversion chart.

Why is Proper Y-Strainer Sizing Critical?

• A filter with too many openings induces higher pressure drops as fluid moves from the inlet to the outlet of the Y-strainer.
• Screen filters with bigger openings permit debris to pass through the strainer. This affects the durability and effectiveness of downstream equipment.

Y-Strainer Sizing Factors

When sizing Y-strainers, process engineers must evaluate the following factors:

• Type of fluid application (what level of fluid cleanliness is required, and which chemical and physical properties do service fluids possess?)
• Desired flow rates across the system
• Pipe sizes
• Size and shape of debris
• Strainer cleaning and maintenance frequency

Y-Strainer Sizing Steps

Engage a piping design expert when selecting Y-strainers for different applications. However, you can adopt the following steps to independently size a Y-strainer and get an idea of what product you should purchase and install in your fluid applications.

1. Determine the desired flow rate. Flow rates across piping systems are defined in gallons or liters per minute. Understanding the desired flow rates makes it easier to choose the correct Y-strainer size capable of sustaining flow rates without losing its filtration efficiency.
2. Identify adjacent pipe sizes. Y-strainer sizes should match those of adjacent pipes. The connection methods should also be compatible. You cannot install a threaded Y-strainer in pipelines having flanged ends.
3. Choose the appropriate mesh size. Mesh size depends on the anticipated type, size, and shape of solids, dirt, and debris in the service fluids. Solids like silt (10-75 microns) will require Y-strainers with a bigger mesh size compared to cement dust (3-4 microns). The screen filters can feature circular, square, or rectangular shapes to trap debris in service fluids.
4. Determine allowable pressure drop across the Y-strainer. Define acceptable pressure drops across the Y-strainer to avoid choosing a filtration system that could increase system pressure drops or restrict fluid flow.
5. Verify the fluid type. Each service media has specific chemical and physical properties. Ensure the screening material and strainer body fabrication materials are compatible with the service media. Some materials experience rapid wear and tear when they come into contact with service media. (Try our free chemical compatibility chart to quickly look up our chemical and materials)

Y-strainer Fabrication Materials

Various materials are used to fabricate Y-strainers to accommodate the operating conditions of different processes. Some common materials include:

Y-strainer body and screen

• Cast iron: A low-cost material with good corrosion resistance. Suitable for low to medium-pressure water, oil, and gas applications.
• Stainless steel: Provides excellent corrosion resistance and is suitable for high-temperature and pressure applications. Useful for corrosive fluids, chemical media, and steam.
• Carbon steel: A strong and durable material that provides good resistance to media corrosion and erosion. Suitable for a wide range of high-pressure and temperature fluid applications.
• Bronze: A corrosion-resistant material with good surface strength and durability. Vital for alkaline fluid applications, where fluids like saltwater can expedite Y-strainer corrosion.
• PVC: Polyvinyl Chloride. A lightweight, corrosion-resistant material suitable for manufacturing Y-strainers for low-pressure applications. Also beneficial for maintaining the cleanliness of mild chemicals.

Sealing materials

Y-strainers have seals to prevent media leakages. Seals extend the service lives of Y-strainers and complement their performance. Seal materials should provide:

• Adequate chemical resistance to reduce media corrosion
• Sufficient protection against media corrosion
• Durable service
• Reliable performance across a wide pressure and temperature range

Some common seal manufacturing materials include:

• Polytetrafluoroethylene (PTFE)
• Ethylene-propylene-diene-monomer (EPDM)
• Fluoro rubber

Y-strainer Installation and Maintenance

Achieving the desired performance characteristics of a Y-strainer does not conclude at the selection phase. The Y-strainer requires proper care during transportation, installation, and operation. Every Y-strainer, regardless of size, needs regular maintenance and cleaning to improve its performance throughout its useful lifespan.

Here are a few things to keep in mind when handling, installing, and maintaining Y-strainers:

• Handle Y-strainers with care. When transporting Y-strainers, be careful not to drop them or expose them to excessive force or pressure. Handle Y-strainers with clean hands or gloves to avoid contaminating the outlet ports. Do not hit strainer ends with blunt objects, as this can distort connection points and affect the tightness of pipe and Y-strainer joints.
• Store Y-strainers and their replacement parts in a clean and dry place. This will help protect them from environmental damage before use.
• When installing Y-strainers in horizontal pipelines, ensure the screen element faces downwards. It may also be necessary to install a bypass line or appropriate control valve, such as a manual ball valve, for isolating the filtration system for routine cleaning or maintenance. When installing Y-strainers in vertical pipelines, ensure fluids flow downwards. This will help ensure debris flows into the screen trap naturally. Improper installations when dealing with vertical piping systems can lead to service fluid contamination by debris.
• Ensure Y-strainers are properly aligned with pipes and adjacent equipment before installation. Pay attention to recommended tolerances between strainers and pipes or other equipment. Minor misalignment can cause the Y-strainer to operate ineffectively.
• Y-strainers require regular maintenance to keep them operational. Maintenance frequency depends on the number of contaminants in the service fluid and the type of service fluid. One way to maintain strainers is to clean the screen filters. You should remove accumulated dirt on time to minimize clogging, which may increase the demand forpumping. Adhere to the manufacturer’s recommendations for cleaning and replacing Y-strainer screens.
• Isolate the Y-strainer before maintenance or cleaning. Closing valves on the sides of the Y-strainer will help relieve system pressure, allowing you to clean and work on the Y-strainer. After relieving the system pressure, open the plug on the Y-strainer. Removing the cap will provide access to the screen. From there, you can remove accumulated debris, inspect the screen material, and replace damaged or deteriorating ones.
• Consider flushing Y-strainers to remove stuck debris from the y-strainer. Ensure the flushing fluid is clean and compatible with the strainer material. It is an effective method to clean filtration screens and rid the Y-strainer of accumulated debris.
• Replace damaged or aging Y-strainer screens with a suitable alternative. Ensure the mesh sizes are equal to avoid fluid contamination. Consult your supplier or original manufacturer to ensure you purchase the correct replacement alternative.

Companies can enhance the performance monitoring of Y-strainers in critical piping systems using advanced systems. Regular performance monitoring ensures Y-strainers operate as intended. They can install pressure sensors or flow meters before and after the Y-strainer to check differential pressure or flow rates across the system. Deviations can indicate clogging or increased accumulation of debris.

Conclusion

Y-strainers are essential components of any fluid application where fluid cleanliness is paramount. These devices remove dirt and debris from service fluids and are designed for easy installation, cleaning, and replacement.

When choosing a Y-strainer, it is important to select one that can effectively remove dirt from fluids. The Y-strainer should also match the adjacent pipe sizes and be compatible with the service fluids to prevent accelerated wear and tear.

To maximize Y-strainer performance, it is important to stock, transport, and install them according to recommended standards. Additionally, it is important to develop effective maintenance programs to inspect, clean, and replace Y-strainer screens. This will improve the durability and effectiveness of Y-strainers in fluid applications.

If you are unsure of which Y-strainer is right for your specific fluid application, our team of experts is available to assist you with any questions. You can reach them during normal business hours by phone or website chat, or by email or voicemail during off-hours.