We are one of the small companies which not only design a technical solution but also prepare a project and its approval with SPP, a.s., and subsequently implement it and hand it over completed to the buyer.
We prepare:
Gas connections
A gas connection serves for the connecting of a user of gas-consuming appliances to a public gas main. It begins with a connection to a gas main and ends before the main shut-off of the gas-consuming appliance. The main shut-off is a part of the household gas line.
The gas supplier establishes a gas-line connection or it is done by some other authorized legal entity or natural person under conditions set by the gas supplier. The owner of the gas line connection is the person who paid the costs for its establishment. The owner is obligated to ensure its operation, maintenance and repair. The gas supplier is obligated to operate, maintain and repair a gas line for payment if its owner requests it.
Principles of the design of the gas connection path
Each building which makes up an independent unit should have an independent connection. Two family houses (a duplex) or scattered buildings on a single parcel of land can share a common connection.
A connection should be direct and perpendicular to the axis of the road along which the gas line runs. The pipe connection must be at a distance of 1 m perpendicularly from the gas main to the peripheral walls of the building at which the connection will end. If the connection is to be led parallel with the foundation of the building, it must be at least 1 m distant from the building. The covering of a gas pipe connection is at least 0.8 m, and a maximum of 1.5 m. The minimum horizontal distance from other parallel engineering networks is 0.4 m and the minimal vertical distance where it crosses with other mains is 0.1 m. The connection is preferentially graded to the gas main with a minimum incline of 0.2%.
The site of ending the connection is designed such that placement of the main shut-off of the gas-consuming appliance corresponds with the conditions of the gas supplier.
The connecting of gas lines connections to a gas main
Low-pressure connections from steel pipes are joined in two ways to a steel gas line, namely:
If the gas main and the gas main connection are from polyethylene, then a T-piece with an electro fusion coupler / fitting is used.
A medium-pressure connection must always be done using a T-piece with a saddle
Installation work for gas lines and connections
Building and assembly work when preparing gas line connections can only be done by contractors (suppliers) who have authorization for this activity and by workers who meet the conditions of professional qualifications.
Prior to the start of the assembly work, the passability of the pipes and their clearance must be visually checked. The welding of pipes is carried out in the field. Fixtures and insulated joints are not assembled on the pipes up until their placement into the trench.
On the day of excavation the piping must be centered and uniformly supported from below and packed with compressed sand (Fig. 3.5). With interruption in assembly work and before laying of the pipes into the trench, free ends must be sealed against the originating of water and dirt.
The pipes, aside from fixtures and demountable joints, must be back-filled when pressure-tested. Fixtures can be packed and buried only after a pressure test, after being inspected by a review technician and after geodetic measurements.
(Fig. 3.5 Textbooks pg. 10/Fig. 3 Placing of pipes in a trench)
Gas lines and polyethylene connections
The joining of a pipe from polyethylene is performed by welding with electro fusion coupler, by the method for straight joints and mechanical joints.
The welding of straight joints can be used only with pipes with an external diameter larger than D 63 mm.
The welding of polyethylene pipes up to D 63 mm inclusive is performed exclusively with electro fusion couplers.
Making a connection from a polyethylene pipe to a gas line from polyethylene is possible only with the help of an electro fusion coupler.
Assembly work with polyethylene pipes, couplers and shut-offs can be performed only up to air temperatures of min. +5o C.
In the summer connecting welds for polyethylene pipes must be done during the lowest daily temperatures, in the early morning hours.
The joining of polyethylene parts of pipes with a metal part is performed with bushings.
Connections, domestic regulation stations (DRS)
Series of steps for making connections, or domestic regulation stations: