Gas-Stop Sentry GS by Maxitrol in Reducer

Area of Application

MR-STOPP is used for gas service lines according to DVGW G459-1-appendix (12/03) for operating pressure ranging from 25 mbar – 5 bar. The MR-STOPP is a FRIALEN reducer coupler with integrated excess flow valve which automatically shuts off the gas flow in the event of pipe damage leading to leaking of gas, caused e.g. by dredging or drilling. The MR-STOPP is best installed into the branch between main and service line, directly behind the tapping valve. The Maxitrol type selection takes place according to the minimal operating pressure of the network and the flow output required by the consumer. The Universal Type Z meets perfectly the practical requirements of the operating pressure range and the necessary flow quantity.

Operation

(see also leaflets on technical data by Maxitrol “SENTRY GS gas flow monitor for underground external networks”) The MR-STOPP is subdivided into types D or Z according to mains pressure range. It shuts off automatically at a defined gas flow as typically occurs where there is damage to the gas service line. The gas flow is stopped immediately and completely. Types D and Z have overflow devices. This overflow quantity allows the pressure in the undamaged gas pipe to increase again in order for the excess flow valve to re-open automatically. Type D, Z: Maxitrol with overflow device: overflow quantities of over 30 l/h require additional passive safety measures in the building according to DVGW-G459-1-B.

Processing Advice

The MR-STOPP is to be processed according to the operation and installation instructions which come with each MR-STOPP. Installation always takes place in the direction of the flow of the medium going from larger to smaller dimensions. The flow direction is marked by arrowson the label. Pressure testing of the gas route using MR-STOPP is authorised up to 10 bar air with the gas flow monitor open.

Operational mains pressure of the component is printed on the type label:

- Yellow type label (type Z) for 35 mbar up to 5 bar

- Orange type label (type D) for 25 mbar up to 1 bar

DVGW test symbols awarded:

reducer coupler MR = DV-8601AU2248. Gas flow monitor = DG-4360BO0438.

The use of this component can be marked in the area of the main shut-off device of the building (appropriate ID card including markings of product data and batches are all included in the initial delivery). FRIALEN safety fittings may be welded with pipes of SDR levels 11. Welding MR STOPP with HD-PE service pipe system takes place using FRIALEN-fusion – tight and with axial force. Installation is prepared according to the general installation requirements (see also “Installation instructions for FRIALEN safety fittings for service and distributor lines up to d 225) (remove oxidic layer/clean).

Good reasons for MR-STOPP:

• Factory made combination of FRIALEN MR reducer coupler and Maxitrol excess flow valve
• Especially important with reducer couplers: triple centre stop provides maximum protection from expressing / position shifting
• The shortening the cold zones through integrated GS is compensated as opposed to the standard coupler
• Exposed heating coil and wide fusion zones allow optimum heat transfer
• Additional barcode for traceability of excess flow valve and coupler (traceability coding)

Excess Flow Valve

• has been individually function checked and adjusted precisely by the factory
• has low pressure loss
• is largely resistant to contaminations in the gas
• its principle has been tried and tested for years
• tolerates pressure increase from low to medium pressure in suitable network
• Type Z can be applied universally from 35 mbar to 5 bar, simple storage, no risk of mix-ups, low operational training needs