cashco DA0 Panduan Pemasangan, Pengoperasian & Pemeliharaan - Halaman 8

Jelajahi secara online atau unduh pdf Panduan Pemasangan, Pengoperasian & Pemeliharaan untuk Pengontrol cashco DA0. cashco DA0 13 halaman. Direct-acting, pressure loaded pressure reducing regulator for steam applications

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VIII. PRESSURE LOADING
1. Loading pressure can be supplied using various
schemes. Please reference LOADING SYSTEMS
on web-site for the schematics of these various
schemes, including:
• pressure unloading using BPV
• pressure loading using PRV
• pressure loading using pilot
• pressure loading using I/P transducer
= ISR Effect + Lower Piston Spring + Lower Piston Spring +
P
LOAD
P
= P
+ [ISR x (P
Load
2
8

SECTION VIII

LOADING PRESSURE FOR
MODEL DA0
APPLIED PRESSURES
Compression Effect
C
Req'd
– P
)] +
x ∆P
V
1
2
C
Max
V
Figure 8: Loading Pres sure Formula
2. The Model DA0 exhibits a deviation in outlet
controlled pressure when the inlet pressure var-
ies; this "effect" is identified as ISR – Inverse
Sympathetic Ratio. Its relative pressure effect
can be calculated from the following equation.
1/2" - 1"
1 1/4" - 1 1/2"
2 1/2" - 4" (65 - 100)
LOWER PISTON
SPRING RANGE
psig
(Barg)
none
(none)
2 - 5
(.14 - .34)
1 - 2
(.07 - .14)
4 - 10
(.28 - 6.9)
SIZE / ORIENTATION – S/O Factor
Body Size
in
(DN)
1/2" - 1"
(15 - 25)
1 1/4" - 1 1/2" (32 - 40)
2"
(50)
2 1/2" - 3" (65 - 80)
4"
(100)
Spring Preload
Orientation Effect
+ LVPS + S/O
Piston Spr.
ISR FACTOR
BODY SIZE
ISR – %
in
(DN)
(15 - 25)
3.0
(32 - 40)
4.0
2"
(50)
2.0
5.4
PISTON SPRING
∆P Piston
LVPS
Spring
psig
(Barg)
(Barg)
0
(0)
0
3
(.21)
2
1
(.07)
1
6
(.41)
4
Orientation
Cover Dome
Cover Dome
on Top
on Bottom
1
2
2.5
3
4
Body Size
Factor
psig
(0)
(.14)
(.07)
(.28)
-1
-2
-2.5
-3
-4
IOM-DA0