Filtro Canasta

SECTION VIII STRAINERS
STRAINERS
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Applications
q q q q

Process Industry Power Industry Chemical Industry Oil and Gas

q q q

Metals and Mining Water and Waste Pulp and Paper

“Y” Strainers
Pressures to 3705 PSIG Temperatures to 800ºF

FEATURES
• Low pressure drop streamlined design • Large strainer screens • Compact end to end dimension • Cast or Fabricated ConstructionEND CONNECTIONS
• Flat Faced • Raised Face • RTJ Flanged • Buttweld • Threaded (NPT) • Socketweld

MATERIALS
• Cast Iron • Ductile Iron • Bronze • Carbon Steel • Low Temp Steel • Chrome Molly • Stainless Steel • Other Materials Upon Request

SIZES RATINGS
• ANSI 125 psig • ANSI 150 psig • ANSI 300 psig • ANSI 600 psig • ANSI 900 psig • ANSI 1500 psig • ANSI 2500 psig
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• Cast- 1/4" (6mm) up to 16" (400mm) • Fabricated - Custom sizes to meet any requirements

Y STRAINERS FEATURES

• Sweat

Y STRAINER DESIGN FEATURES
BODY-COVER FLANGED JOINTS Flanged body-cover joints are designed to meet the requirements of ASME Section VIII, Div. 1 and/or ASME B16.5. For Series 150Y2 and 300Y2 strainers, the body-cover joint is designed using the equations found in Appendix IIof the ASME Pressure Vessel Code. Calculations are performed using standard gaskets and with the existence of a edge moment. The gasket cavity is fully enclosed ensuring proper gasket alignment while preventing unwinding of spiral wound gaskets if used.
Exclusive

Y STRAINERS DESIGN FEATURES

Series 600Y2, 900Y2 and 1500Y2 strainers incorporate a body-cover joint that is in dimensionalaccordance with the flange dimensions specified in ASME B16.5. Among the advantages of this strong leak-proof design is the convenience of using gaskets that are in accordance with ASME B16.20 and ASME B16.21. This feature eliminates the need for dimensionally special gaskets when maintenance is performed.

BODY-COVER THREADED JOINTS The design of a strong threaded body-cover joint is dependent onmany factors. When designing these joints for strainers, calculations are performed taking into account thread shear (ASME B16.34), cover thickness and operating/ gasket seating loads (ASME Sect. VIII, Div. 1). Basic dimensions such as wall thickness and band diameters are in accordance with ASME codes.

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Y STRAINER DESIGN FEATURES
SCREEN SEATING
All Spence Y-Strainers aremanufactured with both

STRAINER SCREENS All Spence Y-Strainers are equipped with screens that have an open flow area many times greater than the pipe nominal crosssectional area. This is important in order to reduce initial pressure drop and decrease the rate in which the pressure drop increases as the strainer screen becomes clogged. As shown in the figure the larger the screen area the lower the rate ofincrease in pressure drop. A Y-Strainer screen must be strong enough to handle the resulting differential pressure that occurs when in service. In general all Spence strainer screens are designed to handle a minimum burst pressure of 50 psid. Spence calculates the burst pressure of screens using the formula:

EFFECT OF SCREEN AREA ON PRESSURE DROP

Pressure Drop

1:1 3:1
0 10 20 30 40 50 %Clogged 60 70 80

St P= R– 0.4t

P S t R

= = = =

Burst Pressure Reduced allowable stress Thickness of screen material Outside radius of screen

Note: Curves are for different ratios of free area to pipe area.

SOURCE: ASME Section VIII, Div. 1, Appendix 1.

Using the above formula, Spence can design and manufacture any strainer screen to suit your specific strength requirements. -383 -

Y STRAINERS DESIGN FEATURES

upper and lower machined seats. This feature eliminates debris by-pass while also acts to securely hold the screen in position when in service. For assembly and disassembly purposes, Spence Y-Strainers are designed so that the screen is securely slid over or into a machined lip on the cover bonnet. This allows the screen to be easily guided into the upper...