What is Shielding Ring?

The purpose of the Shielding / Corona Ring is to avoid corona discharges,Shielding rings are often used in GIS (Gas Insulated Switchgear), power transformers, high voltage bushing terminals, high voltage testing equipments.

Whats 's Corona Shielding Ring?

Shielding / Corona Rings It can be divided into arrester corona ring, lightning protection corona ring, insulator corona ring, transformer corona ring, corona ring of high voltage test equipment, power transmission line corona ring. Corona ring or shielding ring can be used in precision measurement of electrical equipment. Samgor offers designing, manufacturing and installation of corona/shielding ring. A corona ring, also called an anti-corona ring, is a toroid of conductive material, usually metal, which is attached to a terminal of high voltage equipment. The role of the corona ring is to distribute the electric field gradient and lower its maximum values below the corona threshold, preventing corona discharge. Corona rings are used on very high voltage power transmission insulators and switchgear, and on scientific research apparatus that generates high voltages. Corona rings are typically installed on very high voltage power line insulators. Corona rings prolong lifetime of insulator surfaces by suppressing the effects of corona discharge. Corona rings may also be installed on the insulators of antennas of high-power radio transmitters. However, they increase the capacitance of the insulators.

Corona discharges only occur when the electric field (potential gradient) at the surface of conductors exceeds a critical value. The electric field at a conductor is greatest where the curvature is sharpest, and therefore corona discharge occurs first at sharp points, corners and edges. However, some parts of high voltage circuits require hardware with exposed sharp edges or corners, such as the attachment points where wires or bus bars are connected to insulators. Corona rings are installed at these points to prevent corona formation. The corona ring is electrically connected to the high voltage conductor, encircling the points where corona would form. Since the ring is at the same potential as the conductor, the presence of the ring reduces the potential gradient at the surface of the conductor greatly, below the disruptive potential gradient, so corona does not form on the metal points.

Corona shield for tension insulator assembly A corona shield for tension insulator assemblies for use in extra-high and ultra-high voltage overhead transmission lines comprises shielding rings at anchored ends of conductors consisting of a plurality of rings arranged in planes substantially along the longitudinal direction of the conductors so as to surround them and further at least one ring horn arranged perpendicular to the conductors at energized ends of the insulator strings anchoring the conductors, thereby preventing corona discharge from the insulators and line hardware on the energized side of insulator assemblies.

Shielding Ring Specification: Shielding ring is also called corona shielding ring. It is designed for high voltage test purpose, to ensure better corona control effect.

Shielding Ring/Corona rings' Material: Aluminum/Stainless Steel/Copper

Pressure Die casting: Aluminum Alloy AL101 etc. Aluminum: 6061/6063/3A21 Stainless Steel: 304 Copper: C1100


Ring Tube Wall Thickness:2.0mm-10.0mm

MOQ:1 pcs


1. Process: Raw materials(Aluminum, Copper, Stainless Steel etc.) cutting, Pipe bending, CNC machining, Turning, milling ,drilling, grinding, Wire EDM cutting, Welding, Pressure die casting, Polishing finish, Surface treatment, Cleaning, Testing, Assemble and install, Packing, etc 2.Precision Machining: CNC turning, milling, drilling, grinding, assembly

Surface treatment:

Polished Bright/Galvanized/Color Painting/Coating insulating varnish


Steel pallet, wooden pallet and cases with fumigation, wooden cases, etc

Delivery time:

Within 15-25 days after receiving order deposit payment

Transaction term:

EXW, FOB, CIF, DDP, etc.

Payment term:

T/T, L/C, West Union

Product application:

GIS (Gas Insulated Switchgear), Substation, Arrestor, HV bushing, Shunt Reactor, Power Transformer, Power cable (accessory), High voltage laboratory (High voltage test equipments), HV capacitor bank, HV transmission line (overhead line), current transformer, voltage transformer, etc

Shielding rings Corona Ring application in HV transmission line GIS,Aluminun & Steel Bending corona rings

Corona rings/Corona Shields are used primarily as a control, or grading component, in the electrical utility industry for high voltage applications such as switches, substation bus hardware, and dead end assemblies on transmission lines.

Such ring devices of various sizes and configurations act to reduce radio and television inteference which is a direct result of corona, a phenomenon created when the potential of a conductor in the air is raised to such a value that the dielectric strength of the surrounding air is exceeded.