Emerson Fisher MR98 Series - Page 10

Table 6. Type LR128 Main Valve Minimum Dierential Pressures
(1)
MAIN VALVE
BODY SIZE
DIAPHRAGM
MINIMUM DIFFERENTIAL, PERCENT OF CAPACITY
For 90% Capacity For 100% Capacity
In. DN Diaphragm Code Diaphragm Material psid bar d psid bar d
1 25
17E68 (standard) Nitrile (NBR), Low Minimum Di󰀨erential 30 2.1 30 2.1
17E97 Nitrile (NBR), High Erosion Resistance 35 2.5 35 2.5
17E88
Fluorocarbon (FKM),
High Temperature Capability
30 2.1 30 2.1
2 50
17E68 (standard) Nitrile (NBR), Low Minimum Di󰀨erential 18 1.2 19 1.3
17E97 Nitrile (NBR), High Erosion Resistance 24 1.7 24 1.7
17E88
Fluorocarbon (FKM),
High Temperature Capability
18 1.2 19 1.3
3 80
17E68 (standard) Nitrile (NBR), Low Minimum Di󰀨erential 21 1.5 28 1.9
17E97 Nitrile (NBR), High Erosion Resistance 23 1.6 23 1.6
17E88
Fluorocarbon (FKM),
High Temperature Capability
21 1.5 28 1.9
4 100
17E68 (standard) Nitrile (NBR), Low Minimum Di󰀨erential 16 1.1 30 2.1
17E97 Nitrile (NBR), High Erosion Resistance 16 1.1 34 2.3
17E88
Fluorocarbon (FKM),
High Temperature Capability
16 1.1 30 2.1
1. See Table 1 for Type LR128 main valve structural design ratings and Table 2 for Type MR98H pilot rating.
SPRING RANGE,
SPRING PART NUMBER
AND SPRING COLOR
SET PRESSURE
(1)
BUILDUP OVER SET
PRESSURE NEEDED TO
BEGIN OPENING OF
MAIN VALVE
(2)
BUILDUP OVER SET
PRESSURE NEEDED TO
FULLY OPEN
MAIN VALVE
(3)
PRESSURE DROP BELOW
SET PRESSURE NEEDED
TO RESEAT PILOT
psig bar psig bar psig bar psig bar
35 to 75 psig / 2.4 to 5.2 bar
ERAA01910A0
(Green)
35 2.4 1 0.07 1 0.07 2 0.14
50 3.4 1 0.07 1 0.07 2 0.14
75 5.2 1 0.07 6 0.41 2 0.14
70 to 140 psig / 4.8 to 9.7 bar
ERAA01911A0
(Red)
70 4.8 1 0.07 4 0.28 5 0.34
100 6.9 1 0.07 10 0.69 5 0.34
125 8.6 1 0.07 13 0.90 5 0.34
140 9.7 1 0.07 16 1.1 5 0.34
130 to 200 psig / 9.0 to 13.8 bar
ERAA02889A0
(Blue)
130 9.0 1 0.07 14 0.97 6 0.41
150 10.3 1 0.07 14 0.97 6 0.41
175 12.1 1 0.07 17 1.2 6 0.41
200 13.8 1 0.07 17 1.2 6 0.41
100 to 375 psig / 6.9 to 25.9 bar
ERCA04293A0
(Unpainted)
150 10.3 1 0.07 9 0.62 7 0.48
200 13.8 1 0.07 10 0.69 7 0.48
250 17.2 1 0.07 11 0.76 7 0.48
300 20.7 1 0.07 15 1.03 7 0.48
350 24.1 1 0.07 15 1.03 7 0.48
375 25.9 1 0.07 25 1.7 7 0.48
1. Set pressure is dened as the pressure at which the pilot starts-to-discharge.
2. Inlet pressure buildup over the set pressure at which the main valve starts audible ow.
3. Inlet pressure buildup over the set pressure for the main valve to achieve wide-open ow capacity.
Table 5. Build-up Pressure Needed to Begin Opening and Fully Open Main Valve and Pressure Drop Needed to Reseat Pilot
10
Type LR128