
For Commercial and Industrial Applications
ES-88S
Job Name 
Job Location 
Engineer 
Approval 
LEAD FREE
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*
Series 88S
Stainless Steel Wye-Pattern 
Strainers, Threaded Connections
Sizes: 1/4" – 2" (8-50mm)
Series 88S Stainless Steel, Wye-Pattern Strainers with threaded 
connections are used in liquid or steam applications. 
They are built for long service in corrosive, high pressure, and 
high temperature applications. The bottom-threaded cap is 
mated to the body with straight threads and is sealed off from 
contact with the media flowing through the strainer by a cap 
gasket. This prevents corrosion of the threads, thus enabling 
easy servicing and avoiding potential deterioration of the 
threads after an extended period. The cap is tapped for a closure plug. Closure plug is not provided.
  Contractor 
  Approval 
  Contractor’s P.O. No. 
  Representative 
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No. 88S
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Features
• Class 600 stainless steel body
• Wye-pattern
• Threaded connections
• Stainless steel screen
• Stainless steel tapped retainer cap with graphite gasket
Pressure (Non-Shock)-Temperature
Maximum Working Pressure:
 600psi (41.4 bar) at 489°F (254°C) WSP 
1440psi (99.3 bar) at 100°F (38°C) WOG
Materials
Body:   ASTM A-351 Grade CF8M 
Retainer: 
1
/4" – 1" (8mm-25mm)   ASTM A-276 Grade 316 
1
1
/4" - 2" (32mm–50mm)  ASTM A-351 Grade CF8M 
Cap Gasket:  Graphite fiber
Screen:  Perforated stainless steel
stainless steel
stainless steel
stainless steel
*The wetted surface of this product contacted by consumable 
water contains less than 0.25% of lead by weight.
Watts product specifications in U.S. customary units and metric are approximate and are provided for reference only. For precise measurements, 
please contact Watts Technical Service. Watts reserves the right to change or modify product design, construction, specifications, or materials without prior notice and without incurring any obligation to make such changes and modifications on Watts products previously or subsequently sold.

Standard Screens
  SIZE  OPENINGS  STANDARD SCREENS
 in.  mm  in.  mm 
 1
/4 - 2 8-50mm  0.062  1.57 
†Wire mesh liners are available to insert inside the standard 
1
⁄16" perforated screen.
A
1
⁄16" 304SS perf.
Performance Data
For standard 1⁄16" (1.6mm) perforated stainless screen.
300
200
100
9 
8
7 
6
5 
4
3
2
10
9
Liquid Flow (Water) - gpm
8 
7 
6
5
4
3
2
1
0.1         .2   .3  .4   .5 .6 .7 .8 .91             2      3 4 5 6  7 8 9 10
Flow/Pressure Drop Chart
Pressure Drop - psi
in. mm
2 50
1
⁄2 40
1
1
1
⁄4 32
1 25
3
⁄4 20
1
⁄2 15
3
⁄8 10
1
⁄4 8 
Strainer Size
Inlet
NPT 
Flow-Coefficient:
The flow coefficient (Cv) is the number of gallons per minute of 
water flowing through a given size restriction at a pressure drop 
of one psi. To obtain the Cv factor for a given size strainer, read 
the flow capacity curve at intersection with the one (1) 
psi pressure drop.
B
To convert to atmospheres, multiply by .069. 
To convert gpm to lpm, multiply by 3.8
For performance data on nonstandard screens and liners, 
please send for F-C77.
C
Cap
NPT
Dimensions — Weights
 SIZE  DIMENSIONS  WEIGHTS
  A  B  C (NPT)  Cv
 in.  mm  in.  mm  in.  mm in.  mm  lbs.  kgs.  Rating
 1⁄4 8 3 76 21⁄4 57 1⁄4 8 1.3  .5  31⁄2 
 3⁄8 10 3 76 21⁄4 57 1⁄4 8 1.3  .5  6
1
⁄2 15 313⁄16 97 25⁄8 67 1⁄4 8 2.1  .9  101⁄2 
 3⁄4 20 43⁄8 111 33⁄16 81 3⁄8 10 3.0  1.3  17 
 1  25  5
1
 1
⁄4 32 55⁄8 143 47⁄8 124 3⁄4 20 5.8  2.6  45
1
 1
⁄2 40 61⁄4 159 5 127 3⁄4 20 7.0  3.1  60
 2  50  7
3
⁄16 132 33⁄4 95 1⁄2 15 4.5  2.0  28
1
⁄2 191 61⁄8 156 1  25 10.0  4.5  100
A Watts Water Technologies Company
USA: Tel: (978) 688-1811 • Fax: (978) 794-1848 • www.watts.com
Canada: Tel: (905) 332-4090 • Fax: (905) 332-7068 • www.watts.ca 
ES-88S  1325    © 2013 Watts