P818 Series
MECHANICAL SEALS
P818 SERIES
DESCRIPTION
The P818 series is a robust single cartridge seal for slurry application intended to
provide an excellent sealing performance for pumps. As one of the member of RST
Mechanical Seals, P818 is designed to operate in a wide range of process uids. P818
particularly exhibits high performance in the operation of critical process uids of
hydrocarbon, boiler feed water,sour gas, propane and butane, non-ashing
hydrocarbon and ashing hydrocarbon. The improvements in design reliability and
robustness are made possible by the utilisation of sophisticated Finite Element
Analysis (FEA) Engineering Software. These features are further veried by the usage
of ProEights high-end testing equipment, the patented mechanical seal static
tester AccuTEST
and mechanical seal dynamic tester AccuDYN
(Patent
Pending).
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The adoption of modularity concept has made P818 series even more versatile.
Coupled with added interchangeable feature, P818 series seals are able to t in
various conditions, wider range of operating pressures, temperatures and process
uids. This concept ensures that the P818 series seal requires only minimum
change-out on its seal face to suit these conditions, eliminating the need to redesign
a completely different mechanical seal conguration. To cope with temperature
sensitive environment, Low-temperature Inducing Face, ARCAF is designed for this
particular need. ARCAF can be interchanged with other RST Standard Faces to suit
other different operating conditions.
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INDUSTRIAL APPLICATION
Oil & Gas Production
Petroleum Rening
Pipeline
Pulp & Paper
SEAL APPLICATION
ANSI B73.1M and DIN 24960
Pump-Compliant
Centrifugal Heavy Duty Pumps
Centrifugal API Process Pumps
Centrifugal General Purpose Pumps
Positive Displacement Pumps
R.S.T SERIES | P818
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P818 SERIES
DESIGN OVERVIEW
Meet API682 technical design congurations and
requirements
Materials Selection and Design is in accordance with
API682 Standard
RST Design Optimization for seal face design
Flushing Flow pattern is optimised around seal
faces, removing trapped vapour
High efciency buffer circulation system
or
or
Low Pressure Medium Pressure High Pressure
Seal Face
Seal Face
Seal Face
(P818-R)
(P818-S)
(P818-T)
(MODULAR TYPE SEAL FACE DESIGN)
RST DESIGN PHILOSOPY
Advanced FEA Program for Design Optimization
ProEight in-house FEA programs, SIGMA-FEA and
CELC-FEA combined with ANSYS were used extensively
to design the RST mechanical seals. Steady state and
transient conditions coupled with various possible
sealing environment gave a clear overview on the
mechanical seals performance. These software
programs analyse combined seal distortion due to
pressure, temperature, stress distortion and face
loadings.
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R.S.T SERIES | P818
Internal Compression Unit
The main component of the seal is
interchangeable to suit wide range of seal
application.
PERFORMANCE CAPABILITIES
Temperature :
-30 C to 205 C / -20 F to 400 F
Pressures
Up to 21 bar g/300 psig
Speeds
Up to 25 m/s / 5,000 fpm
P818 SERIES
SEAL PARTS
MATERIAL SPECIFICATION
SEAL COMPONENTS
Description
9
1
Seal Face
8
2
7
MATERIALS
Standard
Custom
Resin Impregnated
Carbon
Tungsten Carbide (WC)
Alpha Sintered Silicon Carbide ( -SiC)
Antimony Impregnated Carbon
Reaction Bonded Silicon Carbide (RbSiC)
Reaction Bonded
Silicon Carbide (RbSiC)
Alpha Sintered Silicon Carbide
( - SiC)
Spring Holder
Set Screw
Seat
Throttle Bushing
Seal Face
Shaft Sleeve
O-Ring
Bushing Retainer
Drive Collar
Seat
5
Drive Collar Throttle Bushing Stainless Steel 316L
Thrust Ring Flange
(UNS S31603)
Set Screw
Bushing Retainer Stainless Steel 304L
Shaft Sleeve
( UNS S30403)
Duplex (UNS S31803)
Hastelloy R C-276 (UNS N10276)
Bronze
Titanium Alloy (UNS R56401)
Spring
Stainless Steel 316L
(UNS S31603)
Hastelloy R C-276 (UNS N10276)
Stainless Steel 304L ( UNS S30403)
O-Ring
Fluoroelastomers - Viton
(FKM)
Amine-Resistant
Peruoroelastomer (FFKM)
Low Temp Nitrile Butyl Rubber (NBR)
Teon Encapsulated Viton (VMQ)
Ethylene Propylene Diene Monomer (EPDM)
R.S.T SERIES | P818
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P818 SERIES
DESIGN FEATURES
PERFORMANCE CURVE
Pressure bar (g)
Pressure psig (g)
25
Emission Restrictive Throttle Bushing
350
Carbon vs. Silicon Carbide
at 3600 rpm & Silicon Carbide
vs. Silicon Carbide to 1800 rpm
20
Reversible Seal Head
Uniform-load Multi-spring compression unit
Bolted Auxiliary Gland
300
250
15
200
Spring Protected Design
10
150
Silicon Carbide vs.
Silicon Carbide at speeds
1800 to 3600 rpm
100
50
DESIGN DRAWING
0
20
50
1.5
2.5
80
110
(mm)
140
L3
L1
L2
3.5
4.5
Seal Size
PRODUCT SIDE
ATMOSPHERIC
SIDE
Carbon vs. Silicon Carbide at 3600 rpm & Silicon
Carbide vs. Silicon Carbide to 1800 rpm
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R.S.T SERIES | P818
D1
D2
D3
Silicon Carbide vs. Silicon Carbide
at speeds 1800 to 3600 rpm
5.5
6.5
(inches)
P818 SERIES
DIMENSIONAL DATA
Seal Size *
D1
D2
D3
L1
L2
L3
0254
0285
0317
0349
0381
0412
0444
0476
0508
0539
0571
0603
0635
0666
0698
0730
0762
0793
0825
0857
0889
0920
0952
0984
1016
1047
1079
1143
1206
1270
1333
1397
25.40
28.58
31.75
34.93
38.10
41.28
44.45
47.63
50.80
53.98
57.15
60.33
63.50
66.68
69.85
73.03
76.20
79.38
82.55
85.73
88.90
92.08
95.25
98.43
101.60
104.78
107.95
114.30
120.65
127.00
133.35
139.70
39.73
42.90
46.02
49.25
55.55
58.72
61.11
64.74
67.89
71.07
74.24
77.42
83.85
90.20
90.20
91.80
98.15
102.16
102.16
107.85
111.02
114.30
117.48
120.65
123.83
127.00
130.18
136.53
142.88
155.58
161.93
168.28
41.28
44.45
47.63
50.80
57.15
60.33
62.99
66.68
69.85
73.03
76.20
79.38
85.73
92.08
92.08
93.65
99.92
104.78
104.78
111.13
114.30
117.48
119.99
123.83
127.00
130.18
133.35
139.70
146.05
158.75
165.10
171.45
15.77
14.96
16.92
16.92
15.72
15.72
15.72
15.72
16.51
16.51
16.51
15.16
10.59
14.94
14.94
14.94
13.36
15.09
14.81
15.09
15.09
15.09
15.09
15.09
15.09
15.09
15.09
15.09
15.09
14.38
14.38
14.38
34.37
36.73
36.73
36.73
37.77
37.77
37.77
37.77
40.67
40.67
40.67
43.61
43.61
41.28
41.28
43.82
45.39
40.46
40.46
40.46
40.46
40.46
40.46
40.46
40.46
40.46
40.46
40.46
40.46
44.42
44.42
44.42
49.63
52.37
52.37
52.37
53.98
53.98
53.98
53.98
58.72
58.75
58.75
62.64
65.10
63.50
63.50
63.50
65.07
65.07
63.75
65.07
65.07
65.07
65.07
65.07
65.07
65.07
65.07
65.07
65.07
77.29
77.29
77.29
* All dimensions are in mm
D1 assumes a standard ISO tolerance for shaft (ISO286-2)
Fluid Type
Lubricating Fluid
Light Hydrocarbon
Aqueous Solution
Temperature Range
Weightage
60
81
101
121
161
181
201
80
100
120
160
180
200
220
1.00
0.96
0.90
0.84
0.80
0.65
0.62
40
100
0.75
For further information, please consult our Tecnical Support Engineer.
NOTES:
1. The pressure weightages only confirm to seals with carbon primary rings. Hard face vs hard
face combination seals are not applicable.
2. The listed temperatures are referred to single seals product temperatures. For dual seals,
the listed temperature are referred to the product fluids & buffer/barrier fluids average
temperature.
EXAMPLE FOR DETERMINING PRESSURE RATING LIMITS:
Seal
Product
Temperature
Speed
: 50.8mm/2.000 diameter Type P818
: Lube Oil
: 82 0 C/180 0 F
: 3200 rpm
Using P818 performance curve, the pressure limit is 20 bar g/290.1 psig. From the table
above, apply the weightage value, in case 0.96. For this service condition, the maximum
operating pressure is: 20 bar g/290.1 psig x 0.96 = 19.2 bar g/278.50 psig.
All specifications are based on extensive tests and our many years of experience. The
diversity of possible applications means, however, can only served as guide values. We must
be notified of the exact conditions of application before we can provide any guarantee for a
specific case. Subject prior to change.
R.S.T SERIES | P818
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