Technical Data
The Krysalis™ Below Ground Module
Introduction
A purpose designed Below Ground Gas Control Module
The Krysalis™ contains all the elements of a conventional gas pressure reduction station. The working parts are contained in a removable cartridge housed in a ductile iron body which is installed underground into the gas mains. Above ground is a ‘Vent Stack’ which contains vent pipes for atmospheric reference pressure and the relief valve together with the necessary instrumental and pressure reference points and provision for mechanical or electronic pressure recording device. The Krysalis™ Gas Control Module is manufactured and marketed under an exclusive worldwide licence from British Gas
Take a look at these benefits:5 Compact Design with all control elements contained within an underground housing 5 All control elements are combined in a lightweight removable cartridge which can be lifted by one person 5 Noise levels virtually eliminated 5 Simplified Planning
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5 Separate filter chamber - allows removal of the filter element, without the need to remove the main control unit 5 Easily adaptable to suit various types of control systems, e.g. Clocking, Profiling etc 5 Totally buried design allows installation in a city or rural location.
Krysalis 2
Krysalis 4
Krysalis 7
Maximum Inlet Pressure (Bar g)
2.0
4.0
7.0
Minimum Inlet Pressure (Bar g)
0.2
0.2
0.5
Outlet Pressure
13 to 100 Mbar g
Configuration
Slam//Active
Operation
Pilot Control
Over Pressure Cut-Off Valve
40 to 200 Mbar g
Combined Under/Over Pressure Cut-Off Valve (UPCO/OPCO)
OPCO 30 to 250 Mbar g UPCO 10 to 50 Mbar g
Internal Relief Valve
30 to 120 Mbar g
Corrosion Protection
Module -coated with glass filled epoxy coating
Connections: Flanged to BS4504 PN16/DIN2633
Inlet 150mm
Technical
Service Conditions
Outlet 200mm
Major Components Filter
200 or 50 Micron Stainless Steel Element 5 micron resin impregnated paper
Regulator
Pilot controlled piston type regulator, inlet pressure balanced, open at rest.
Safety Cut Off Valve
Over Pressure Cut-Off (standard) Under/Over Pressure Cut-Off (optional)
Pilots
‘J’ Governor – Series 241R ‘K1 & K2 ’ Pilot - Series 226MK
Safety Relief Valve
Series 226 MR
Stream Discrimination Valve
Series 581 Waferchek Valve
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Performance
Capacities in scmh (SG 0.6) Outlet Pressure
0.15
0.5
Inlet Pressure in Bar g 1.0 2.0 4.0
20 Mbar g
2000
3500
5000
7500
75 Mbar g
1600
3000
3800
6500
6.0
7.0
8000*
8000*
8000*
8000*
8000*
8000*
* Velocity at the outlet flange is limited to 65 m/sec. Note, if the valve travel limitor is fitted the valve opening is reduced by 50% giving a reduced capacity – Contact BDRMG for details
Pipe Velocity Limits The maximum capacities given in the table above do not take into account pipe velocity restrictions, which will be dependent upon the inlet & outlet pipe size: Typically:
Inlet Velocity = 20 m/sec
Outlet Velocity = 40 m/sec
Accuracy Class & Lock-up The main regulator has a performance characteristic that exhibits very little droop over its operating range, also due to the excellent inlet pressure balance, the effect of changes of inlet pressure on the outlet pressure are minimal.
3
Inlet Pressure Bar g
Accuracy Class (AC)
Lock-up Class SG (Low Po)
Lock-up Class SG (High Po)
0.2 to 2.0
5%
20%
10%
0.2 to 4.0
10%
20%
15%
0.5 to 7.0
15%
20%
15%
0.2 to 7.0
20%
30%
20%
To assist with the ease of installation a number of Pre-Packaged Single and Twin stream arrangements are available. These arrangements are available with conventional steel pipework and manifolds or alternatively with PE pipework and manifolds. The use of PE eliminates the need for costly pipe protection against corrosion and makes the installation compatible with most of the new systems now being installed. Each Option comprises:5 Inlet & Outlet Isolating Valves 5 Krysalis™ Gas Control Module 5 Interconnecting Pipework (PE or Steel) 5 Optional Inlet & Outlet Manifold 5 Single or Twin Stream Vent Stack
Single Stream Option with PE pipe
Pre-Packaged Modules
Standard Options
For the full range of options please Contact BD-RMG
Optional Extras 5 Electronic Clocking 5 Pressure Profiling 5 Telemetry 5 Purpose designed Vent Stacks for various control systems 5 Pressure Logger or Chart Recorder
Optional Pressure Profiling System
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Construction 5
Sectional Arrangement
Operation
Schematic System Diagram
Shaded lines define extremity of the GCM body
The Krysalis™ is operated by an auxiliary rail control system. A small flow of gas at inlet pressure is taken from a position on the cartridge between the slam shut valve (SS) and the main regulator (M). This gas is filtered (F2) and then pre-regulated by a regulator (J) before passing through a restrictor pipe (D) and then through two pressure control pilot regulators (K1) and (K2) before being bled into the outlet main. A pipe connected to the inlet of the K1 control pilot delivers gas from the auxiliary rail to power the diaphragm actuator of the main regulator. Each control pilot senses outlet pressure through a control line connected to the outlet of the installation. With a demand for gas, the outlet pressure falls slightly and the control pilot opens in response to this, causing a flow of gas through the auxiliary rail, thus reducing pressure on the outlet of the restrictor pipe.
This allows gas to bleed from the main regulator to open as the force opposing the main regulator spring decreases. The system is designed so that only a small change in outlet pressure (sensed by the control pilot) is needed to stroke the main regulator. With no demand, the outlet pressure rises slightly to close-off the control pilot, thus temporarily preventing the flow of gas through the auxiliary rail. This allows full outlet pressure from the ‘J’ regulator to be imposed upon the diaphragm of the main regulator, thus forcing the main regulator to the closed position. In practice, the control pilot continuously modulates the flow through the auxiliary rail to maintain the main regulator in the optimum position to satisfy the flow demand whilst maintaining an acceptable outlet pressure.
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Dimensions & Weights
285
670
530
658
Connections: (flanged PN16)
Weights:
Inlet - DN150 Outlet - DN200 Body 250Kg Cartridge 30Kg
All dimensions in mm
The Krysalis™ Below Ground Module is one of many gas control products manufactured by Bryan Donkin RMG. With almost 200 years experience you can be sure of the ideal solution to meet your requirements...
Enterprise Drive, Holmewood, Chesterfield, England. S42 5UZ UK Tel: (01246) 501501 UK Fax: (01246) 501500 Int Tel: +44 1246 501501 Int Fax: +44 1246 501500 e-mail: sales@bdrmg.co.uk website: www.bdrmg.co.uk A Member of the
Group
The Bryan Donkin RMG Gas Controls policy is one of continuous improvement and development. The company reserves the right to change and introduce improved designs without notice.
KRY.470.00.0802