PLUG VALVES :: STANDARD :: FEATURES MMVI is glad to show you its range of plug valves DELTA PLUG. The DELTA PLUG range can be supplied in two different kind of design: 1) LUBRICATED STANDARD This kind of design previews that the larger part of the plug is oriented towards the upper part where the shaft seal is placed. The plug valve is equipped with a bolted bonnet that maintains the connection in the case where the packing is removed. The packing has two main functions: - the first one is to maintain the pressure in order to avoid any infiltration through the shaft; - the second one is to maintain the shaft in its correct position into the body. The lubricator permits the plug lubrication, injecting the grease into the reservoir through a nipple that avoids the leakage of grease. The grease recharge can be done even when the valve is under pressure on the line. Thanks to the lubricating grooves the plug is always lubricated and this system avoids any grease leakage even during the rotation phase. 2) LUBRICATED BALANCED PRESSURE This kind of design previews that the larger part of the plug is oriented towards the opposite part of the shaft seal. This kind of valve can work under pulses, balanced pressures and high static pressure. The advantages of these valves are the following: - pressure balancing trough the chambers placed in the upper and lower part of the body and through the   holes placed on the plug; - easy maintenance even after a long time in open/closed position; - should the plug and body lock together, it is possible to release by injecting lubricant through the   greaser with the valve in service; - When required the valve is equipped with double operating grease injectors. Upon request we can realise multiport plug valves (T, L-shaped and with 4 ways). CONSTRUCTIVE VERSIONS The DELTA PLUG range can be manufactured with the following connection: - FLANGED with flanges at the two ends. - BUTTWELDING with two welding bevels made in accordance with standard and with the customer   requests. The welding bevels are equipped with centering ring for the positioning and line welding.