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These components play very different roles within a pipeline, yet they work together to ensure reliability, protection, and controlled flow. In today’s blog, we’re taking a closer look at what arrived on the van, how each valve functions, and why these types of products remain critical in modern engineering environments.
While valves are often overlooked in favour of pumps, tanks, and larger equipment, they remain some of the most important safety and efficiency features in any system. Understanding how they work not only helps with specifying the correct product, but also with long-term maintenance and performance planning.
Cast Iron Y Strainers (8″ & 5″)
Y strainers are one of the simplest yet most important protective devices in a pipeline. Their primary job is to prevent debris, rust flakes, scale, and contaminants from progressing through the system and causing damage to pumps, flow meters, control valves, and sensitive downstream equipment.
Why a “Y” Shape?
The angled body design (shaped like a Y) allows fluid to pass through a mesh or perforated strainer element, while dirt is trapped in a pocket that can be emptied when required. The angled design reduces pressure loss and ensures the strainer can be installed both horizontally and vertically, depending on flow direction.
Key Benefits of Cast Iron Y Strainers
Ideal for large pipelines, especially in water distribution, industrial cooling, and fire protection systems.
Durable cast iron construction, offering excellent strength and long service life under PN16 operating pressures.
Removable strainer screen, making maintenance straightforward.
Helps protect high-value downstream components, reducing long-term operating costs.
For 8″ and 5″ systems, strainers are particularly important because the cost and complexity of replacing large pumps or automatic valves increases significantly. Installing a Y strainer early in the pipeline is a simple way to avoid future failures.
Flanged Butterfly Valves (8″ & 5″)
Also in our delivery were flanged butterfly valves. Butterfly valves are widely used for isolation and throttling because they offer quick shut-off, compact dimensions, and a design that integrates well into large pipelines without excessive weight.
How Butterfly Valves Work
A disc mounted on a central shaft rotates to open or close the flow path. In the fully open position, the disc aligns parallel to fluid flow, minimising obstruction. In the closed position, the disc turns perpendicular to the flow, sealing against the EPDM liner.
Characteristics of Modern Butterfly Valves
Quarter-turn operation (only 90° from fully open to fully closed)
Lightweight and space-efficient compared to gate valves
Suitable for water, air, and many neutral fluids
Low torque requirements, allowing the use of simple levers or gear operators
The valves arriving at our depot include stainless steel discs and EPDM liners, suitable for potable water and general industrial applications.
Typical Applications for Butterfly Valves
Water distribution networks
Process cooling systems
HVAC plant rooms
Irrigation networks
Pumping stations
When working with 8″ and 5″ pipelines, ease of installation becomes a major consideration. Butterfly valves have the advantage of requiring fewer bolts and a much smaller footprint than traditional gate valves, making them extremely practical in large-diameter systems.
Dual Plate Wafer Check Valve (8″)
Check valves are responsible for preventing backflow, one of the most important safety considerations in any pipeline. The dual plate wafer check valve included in this week’s delivery is designed for PN16 systems and features a compact design that fits between flanges without the need for extended face-to-face lengths.
Below are the key details taken directly from the technical sheet supplied with the product:
Pressure & Temperature Specifications
Pressure: PN16
Temperature Range: -10°C to 120°C
These parameters make the valve suitable for chilled water, heating circuits, and a wide range of industrial water applications.
Material List
Body: Cast Iron EN-JL1040
Disc: Stainless Steel 304
Seat: EPDM
Hinge Pin & Stop Pin: Stainless Steel 420
Pin Retainer: Stainless Steel 304
Washer: PTFE
Gasket: EPDM
The combination of a cast iron body and stainless-steel internals provides durability while keeping weight manageable for installation between PN16 flanges.
Understanding the Dual Plate Design
The valve incorporates two spring-loaded plates that open when fluid flows forward and snap closed when flow reverses. This “dual plate” or “dual door” mechanism offers three key advantages:
Reduced water hammer: The spring-assisted closure prevents sudden slamming.
Minimal flow restriction: The split disc reduces obstruction compared to solid swing check valves.
Compact installation: The wafer design fits neatly between flanges, saving space.
Sizes and Cracking Pressure
The provided sheet outlines dimensions from 2″ to 24″, with the 8″ model featuring:
A: 272 mm
B: 95 mm
C: 210 mm
Cracking Pressure: 150 mBar
Weight: 13.5 kg
A cracking pressure of 150 mBar ensures the valve opens with low forward pressure, ideal for low-velocity flow systems such as gravity return lines or secondary water circuits.
Pressure Drop Chart
The included performance chart highlights pressure loss at different flow rates. While the graphical lines can look complex at first glance, the key takeaway is that dual plate check valves produce lower pressure drops compared to many alternative backflow prevention options.
How These Valves Work Together in a System
Although each component delivered today serves a distinct purpose, they are often installed in complementary positions within a pipeline:
Y Strainer → Butterfly Valve → Check Valve
It is common to see this order within pump discharge lines or distribution networks.
The Y strainer protects the moving parts in the butterfly valve.
The butterfly valve provides shut-off for maintenance.
The dual plate check valve prevents reverse flow when pumps stop.
This arrangement forms a balanced combination of protection, control, and safety.
Why Components Like These Remain Important
As water systems grow more efficient and more automated, the reliability of core mechanical components remains vital. Even with digital controls and smart monitoring, the fundamentals of flow protection and isolation have not changed.
Long-Term Efficiency
Small components like strainers and check valves protect expensive equipment from damage, reduce downtime, and improve overall performance.
Maintaining Water Quality
EPDM-lined valves and stainless-steel discs ensure compatibility with potable water, making them suitable for municipal systems and public buildings.
Safety & Compliance
Preventing backflow is not optional, UK water regulations require suitable devices in many systems. Dual plate check valves meet these expectations without adding unnecessary bulk or weight.
Supporting North Wales Industry
Deliveries like this are part of our daily operations at Collister & Glover. Whether supplying contractors, mechanical engineers, or industrial facilities, we work hard to maintain consistent stock of the products that local businesses rely on.
These valves will soon be part of water systems, cooling loops, plant rooms, and process lines across the region, supporting everything from manufacturing to commercial heating installations.
