4
3 80 7½ 190.50 6 152.40 4 ⅝ - 11  2 50.80 2½ 63.50
4 100 9 228.60 7½ 190.50 8 ⅝ - 11  2 50.80 2½ 63.50
6 150 11 279.40 9½ 241.30 8 ¾ - 10  2 50.80 2½ 63.50
8 200 13½ 342.90 11¾ 298.45 8 ¾ - 10  2¼ 57.15 2¾ 69.85
10 250 16 406.40 14¼ 361.95 12 ⅞ - 9  - - 3 76.20
12 300 19 482.60 17 431.80 12 ⅞ - 9  - - 4 101.60
14 350 21 533.40 18¾ 476.25 12 1 - 8  - - 4½ 107.95
16 400 23½ 596.90 21¼ 539.75 16 1 - 8  - - 4¾ 120.65
18 450 25 635.00 22¾ 577.85 16 1⅛ - 7  - - 5½ 139.70
20 500 27½ 698.50 25 635.00 20 1⅛ - 7  - - 5½ 139.70
24 600 32 812.80 29½ 749.30 20 1¼ - 7  - - 6 152.40
26 650 34¼ 869.95 31¾ 806.45 24 1¼ - 7  - - 6 152.40
30 750 38¾ 984.25 36 914.40 28 1¼ - 7  - - 7 177.80
36 900 46 1168.40 42¾ 1085.85 32 1½ - 6  - - 8½ 177.80
42 1050 53 1346.20 49½ 1257.30 36 1½ - 6  - - 9 203.20
48 1200 59½ 1511.30 56 1442.40 44 1½ - 6  - - 9½ 241.30
54 1350 66¼ 1682.80 62¾ 1593.90 44 1¾ - 5  - - 10½ 241.30
60 1500 73 1854.20 69¼ 1759.00 52 1¾ - 5  - - 11 266.70
CLARKSON SLURRY KNIFE GATE VALVES
KGA+
4 OPERATION
TABLE 3 - BOLTING DIMENSIONS
Valve size
Flange 
diameter
Bolt circle 
diameter Bolt holes 
no.
Bolt 
size/thread
Bolt lengths (see note)
Without retainer flg. With retainer flg.
NPS DN inch mm inch mm UNC inch mm inch mm
NOTES
• Flange dimensions per ASME B16.5/150 for NPS 2 - 24 (DN 50 - 600) and MSS SP44 for NPS 26 - 60 (DN 650 - 1500).
• Type B standard washers are not included in bolt / stud sizing.
• Mating flange thickness assumed to match ASME B16.5/150 for NPS 2 - 24 (DN 50 - 600) and MSS SP44 for NPS 26 - 60 (DN 650 - 1500).
1.  Clarkson slurry knife gate valves are 
suitable for on-off service only. They are 
notto be used in a throttling application.
2.  To close the valve and provide isolation, 
the actuator (handwheel, bevel gear, 
air/hydraulic cylinder or electric motor 
actuator) moves the metal gate in a linear 
motion between the elastomeric sleeves 
to shut off the flow. To open, reverse the 
operation and the gate moves up and out 
from between the sleeves, opening the 
valveport.
3.  Matching elastomer sleeves seal against 
each under a high compression load 
when the valve is open, creating the valve 
pressure vessel. When the valve is closed, 
the sleeves seal against the gate face, 
isolating upstream from downstream. 
SeeFigures 2 and 3.
 Note: it is normal for the KGA+ to discharge 
media during opening and closing cycles. 
This helps prevent any solids from building 
up between the sleeves that would prevent 
a tight seal when the valve is fully open or 
closed. Discharge can be controlled with 
the use of an optional splash guard. Do not 
install valve over walkways, electrical or 
other critical equipment without the use of 
splash guards or similar considerations.
4.  As the gate strokes, a gap is created 
between the facing sleeves, allowing any 
media that could potentially clog or jam the 
valve to be purged out from between the 
sleeves, and potentially expelled outside 
thevalve housing to atmosphere.
5.  The KGA+ valve incorporates a built-in 
clean-out area at the base of the housing 
assembly. The clean-out area may be 
enclosed by an optional, removable 
splash guard assembly. This splash guard 
will allow controlled drainage of any 
accumulated solids that may prevent full 
gate closure. Flush water can be used to 
improve the drainage efficiency. With the 
splash guard in place, any solids, slurry, or 
flush water ejected from the valve can be 
handled in a controlled manner. See Section 
‘Installation instructions for splash guard’.
6.  All valves should be operated within the 
design pressure and temperature ranges. 
Under no circumstances should the valves 
be operated at conditions outside these 
parameters.
 Note: actuated Clarkson valves have a 
maximum recommend stroke speed of 
1” (25 mm) per second. Exceeding this 
speed can shorten sleeve life and may 
void warranty. Speed controls provided by 
factory will require adjustment in the field 
to obtain proper stroke speed against actual 
operating conditions.