You can find more information on our web, so please take a look.
Filtration systems are crucial in various sectors, from municipal wastewater treatment plants to food processing and chemical manufacturing. These industrial filtration processes are designed to remove unwanted solid particles that can cause wear on pump equipment, leading to breakdowns and work stoppages. Among the methods employed, industrial strainers are the primary defense line to ensure product quality, prevent premature breakdowns, and maintain operational efficiency.
Y-line strainers and inline strainers are the two most commonly used types for industrial applications. Given strainers' significant role in these systems, having a good grasp of their functionality within pumping systems is vital for pump operators and maintenance workers. While understanding the differences between a Y-strainer and an inline strainer is key, knowing which one suits a specific purpose is equally important.
Two Strainer Types & How They Differ
Strainers are used to filter solid contaminants from a variety of fluids. They remove particles suspended within a liquid to protect downstream equipment from damage, including pumps. Two of the most widely used types are often referred to as y-strainers and inline strainers. Unlike filters, which remove smaller solids from fluids, strainers remove larger particulate matter.
A strainers primary purpose is to protect equipment from damage. Y-strainers and basket-shaped inline strainers are used in water distribution systems, affecting the quality of drinking water received. While both have advantages and disadvantages in certain applications, both essentially do the same job of removing larger particles within a flowing liquid.
Both types of strainers are named according to their positioning in the pumping system and shape. Basket-style inline strainers work only when installed horizontally, while Y-strainers have greater flexibility in how theyre installed and can even be installed vertically. Additionally, both types of strainers can be positioned inline, which can involve bolting, threading, or welding a strainer with parts arranged in a line.
What is an Inline Strainer?
Also known as T-strainers, T-line strainers, or simplex strainers, inline strainers - or basket strainers due to their shape - are placed before nozzles, pumps, or valves to trap debris that could damage sensitive equipment. Typically resistant to solvent solutions with salt and mineral-based acids, inline strainers are easy to clean and maintain with minimal monitoring.
Materials from which inline strainers are made often determine their application:
- Cast copper inline strainers: Durable and corrosion-resistant, inline strainers made from cast copper are used in instrument control systems, dental equipment, and apparatus used for processing beverages, to protect equipment like pumps and control valves.
- Nylon inline strainers: Able to resist corrosion, humidity, and high temperatures, nylon inline strainers protect sensitive equipment like pumps and valves within sprayers for agriculture, pressure washers, and medical devices.
- Polyamide inline strainers: A thermoplastic thats reinforced with fibers made from glass, polyamides offer inline strainers greater rigidity and strength while providing better corrosion and heat resistance; used to protect pumps, control valves, and other similar equipment inline, the strainers are used in higher flow industrial processes.
- Polypropylene inline strainers: A lightweight thermoplastic polymer, inline strainers made from this material resist abrasions, corrosion, and impact while also offering greater surface hardness; these strainers are typically used to protect control valves, pumps, and regulators in process equipment for food processing, wastewater treatment, and similar industrial applications.
- Stainless steel inline strainers: Able to withstand corrosion from harsh chemicals and corrosive fluids, stainless steel is often used in applications involving corrosive gases, fluids, and oils where high temperatures and pressures are issues; inline strainers made from stainless steel are used to protect an array of processing equipment for chemical manufacturing, food processing, pharmaceutical manufacturing, water management, and other industrial applications.
Other materials can also be used for making inline strainers, including steel, other ferrous alloys and even brass. The material's properties will often determine what application an inline strainer would best serve.
What is a Y-Strainer?
Y-strainers mechanically filter out solids from pipelines carrying liquids or occasionally gases, albeit with a distinct shape. Unlike the conventional basket design in inline strainers, Y-strainers boast a straining component crafted from wire or perforated mesh. These strainers are employed in pipelines to safeguard control valves, meters, pumps, regulators, steam traps, and other processing equipment. In numerous scenarios, Y-strainers emerge as the most cost-effective choice, particularly when dealing with a relatively small volume of material that necessitates removal.
Y-strainers require less frequent cleaning than inline strainers due to their lower material collection. This infrequency is advantageous, although cleaning involves shutting down the line and manually washing the screen after removing the strainer cap. Typically utilized for fluids or gases with fewer impurities, Y-strainers can also have a connector for screen cleaning without disassembling the strainer body.
Industries that use Y-strainers include:
- chemical processing
- food and beverage
- marine
- natural gas
- petroleum
- pharmaceuticals
- pipelines
- power generation
- water treatment
Y-strainers play a crucial role in safeguarding downstream components across various sectors. Primarily employed in water systems, they effectively filter out gravel, sand, and debris that could obstruct or harm equipment. Thanks to their design, they excel in high-pressure settings like steam applications. Moreover, Y-strainers adeptly manage pressurized air, natural gas, and the elevated temperatures typical in such operations.
Materials for Y-strainers can also differ considerably due to the wide variance in applications and industries in which these strainers are used. For this reason, Y-strainers meant for applications involving steam or natural gas wont be made from carbon steel, which doesnt stand up well under high pressures and temperatures. Instead, Y-screens might be made of Chromoly steel, such as , that can withstand furnaces or natural gas production conditions.
A Comparison: Y-Strainers vs. Inline Strainers
Besides their shape and where theyre positioned, other basic deviations exist between Y-strainers and inline strainers. Generally, Y-strainers provide greater flexibility, though they can handle less flow, so should be used for applications that involve straining out fewer contaminants. Inline strainers of the basket variety work better for applications where downtime isnt an issue and materials contain far more contaminants.
Advantages Y-strainers offer include:
- Allows for more compact straining.
- Flexible positioning, allowing for either horizontal or vertical installation.
- Made generally from stainless steel.
- Operates well under higher pressures and temperatures.
Advantages of inline strainers include:
- Can handle flowrates over 150 gallons per minute.
- Comes in both simplex and duplex varieties.
- Enables servicing without interrupting flow.
- Made from a wide range of materials.
- Works well for pipelines that handle constant flow.
Y-strainers and inline strainers are commonly used in pipelines. Y-strainers are versatile, suitable for filtering both liquids and gases, whereas inline strainers are more effective at filtering liquids.
Hayes Pump: Your Source for Pump Strainers
Regardless of what inline strainer youre looking for, Hayes Pump has what you need to keep contaminants out of your pumping system. We carry all inline strainers, including duplex, metallic, plastic, simplex, and Y-strainers. To learn more about our inline strainers and other pump system implements, contact the pump experts at Hayes.
Download PDF
A Comparison of traditional Y Strainers and Basket Strainers to the new LPD Strainer
Considering the y-strainer as a critical, energy-saving piping system component
Pumps, chillers, boilers and heat exchangers are the high-profile piping system components targeted to improve energy efficiency. More obvious in their energy consumption, these units are constantly being re-engineered, tested, measured and introduced to the market with improvements that measurably improve energy savings.
Other low-cost components in the system are routinely plugged into a design, accepted for their role in creating pressure drops and turbulence since there are no alternatives. One of these components is the strainer.
Todays traditional strainer design was actually introduced over 100 years ago. The strainer was created to protect expensive equipment, such as pumps, chillers, boilers and heat exchangers by removing debris from fluid before it reached these components. But, a century ago energy consumption was not a consideration and energy efficiency was an unknown concept.
It is now better understood how strainers add pressure top due to their antiquated design and a screen that accumulates debris and increasing pressure loss. This pressure loss translates into pumps increasing energy consumption. Its time to consider the strainers energy consumption.
A new strainer has recently been introduced. The new LPD y-strainer is redesigned from the ground up to provide superior pressure drop. Its internal geometry has been completely re-engineered, which also allows for a much larger screen with significantly increased debris capacity.
Following are comparisons between the centuryold y-strainer and basket strainer designs and the new LPD y-strainer to assist in making a more informed decision on which component is right for your piping system.
Y-strainers
Y Strainers are widely used in hydronic systems and have been the most common type of strainer because
1) Unlike basket strainers they can be installed in horizontal and vertical pipe runs.
2) They can be blown down.
Yaxing Valve contains other products and information you need, so please check it out.
3) They are less expensive than basket strainers.
Basket Strainers
Basket strainers are the go to selection for strainers in open systems such as cooling towers. There were several perceived reasons for this.
1) Basket strainers have a higher capacity over the traditional Y strainer.
2) Basket strainers have a lower pressure drop.
3) Basket strainers are available with clamp on covers making cleaning the screen easier, then it would with a traditional Y strainer.
Taking a closer look at these points we will address some long-standing misconceptions about strainers, and discuss alternatives that will improve piping design.
Figure 1
Figure 2
The redesign of the strainer started with the basic Y strainer to take advantage of the versatility of vertical and horizontal installation, the ability to be blown down and the lower cost.
A CFD analysis and quickly confirmed the obvious, that the bridgewall universally used in Y strainer design caused restriction and an abrupt change in direction of flow, a big contributer to pressure drop.
In the new design, the bridge wall has been eliminated. See CFD analysis results below.
The bridge wall restricted flow and created turbulence in the strainer resulting in increased pressure loss (Figures 1 and 2).
The next design improvement the pitch of the screen. Screen pitch was lowered from 45º to 22.5º.
Figure 3A: The old, traditional strainer, left, has a steeper screen pitch. Right, the new LPD Y-strainer has a shallower pitch allowing the screen to be much longer.
The lower pitch resulted in a much larger area of the screen to be in the flow path. This resulted in lower internal velocity and lower pressure drop (Figures 3A and 3B).
The change in pitch now allowed the screen to be much longer. Then as part of the redesign the casting was made larger to increase screen diameter (Figures 4A and B).
The result was not only a screen with much larger area for debris capacity, but a much larger screen area in the fluid flow.
Figure 4: Comparisons between traditional strainer screens and the new LPD Y-strainer
Size
Basket Strainer Screen Area in²
Y-Strainer Screen Area in²
LPD Y-Strainer Screen Area in²
2
29.97
51.55
52
2.5
45.11
70.01
84.6
3
78.2
61.34
99
4
108.44
99.64
147
6
176.75
242.72
317
8
310.03
411.16
515
10
457.06
610.51
745.2
12
691.07
835.53
.1
Figure 4B: Four-inch strainer screens. Basket strainer screen, left, y-strainer screen, center, and LPD Y-strainer screen, right.
The results of all these design improvements result in a major improvement in the CV values of the LPD strainer, in some sizes almost double that for the old fashioned Y strainer and substantially better than a basket strainer as shown in (Figure 6).
Note, the CV values shown (Figure 6) are results from independent testing. We have found several basket strainer manufacturers literature that had much higher values that we believe to be overstated.
Probably the best feature of the LPD is its ability to capture debris. The same amount of debris in an LPD will have far less of an impact than it would in a traditional Y strainer or basket strainer. Using a dollar bill to represent the same debris blockage in each screen (Figure 7), it is obvious how much more unobstructed screen area is available in a 4-inch LPD vs a traditional, old-style 4-inch strainer.
Figure 5: Cv comparisons between traditional strainer screens and the new LPD Y-strainer
Size
Cv
Basket Strainer
Cv
Y-Strainer
Cv
LPD Y-Strainer
4
326
232
457
6
614
976
8
888
10
Figure 6: Independent testing results comparing a clean LPD Y-strainer, and various amount of debris blockage, to a completely clean competitor strainer.
To demonstrate how the difference in pressure drop is even more dramatic between the two LPD and the traditional y-strainer, a test compared an LPD strainer with 92.7 in2 of blockage (29% blocked) still has a better CV than a 100% clean competitive strainer.
The larger capacity of the LPD strainer screen also means that you do not have to blow it down as often as a standard Y strain reducing maintenance costs.
Y-strainer vs Basket strainers
Basket strainers are considered easier to clean than y strainers. If shut off valves are properly located, the basket strainer does not lose water or require the system be drained to clean.
However, the LPD can be blown down where the basket strainer cannot. If blown down, the LPD may not even need to be cleaned.
The basket strainer is available with a clamp-on cover requiring only one bolt to be loosened to remove the cover. Depending on the manufacturer, clamp-on covers result in a lower pressure rating than a standard flange cover. This is normally a big advantage over a traditional Y strainer using a standard pipe flange for a cover. However, the new LPD design features a cover with 4 or 6 bolts depending on the size. Additionally, the cover of LPD strainers 10 and larger are hinged for easier handling.
Whenever a cover is removed from any of the traditional basket strainers or y strainers there is often a custom gasket that needs to be replaced. The LPD strainer uses a reusable O-ring seal.
In conclusion, it is taken for granted that science and technology has improved virtually everything around us. However, it has been over 100 years since technology has tackled the inherent flaws in y-strainer design. With the introduction of the new LPD y-strainer, significant energy savings have been captured with its new design. The LPD y-strainer is a significant improvement over other strainers, making it the best performing strainer on the market today.