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Made by Mogas, USA           Catalogue# 010253000                  Back

 

Ball

The Mogas mate-lapping process eliminates leaks through the ball and seats.

Standard

  • 410SS/CCC - HVOF applied

Optional

  • 17-4PH, 329SS, 316SS, Inconels, Ferralium 255, Hastelloys, Monel, Alloy 20, Titanium, Zirconium

Features

  • Machined and lapped to as perfect a sphere as possible
  • Every ball and seat are "blued" to assure that 100% contact is achieved across the entire seat face
  • Coated to at least a hardness of 62 Rc
  • Oversized which allows 5 - 7% over travel which reduces wear and eliminates an unexpected opening due to actuator stops being out of adjustment
  • Edges of the bore are blunted to prevent coating fracture
  • Double arcuate cut - available for high pressure or severely abrasive applications

 

The Mogas Double Arcuate Cut

Double Arcuate Cut

Mogas developed the Double Arcuate Cut in response to abrasive, high velocity services that were damaging to the ball and seat during the first few degrees of operation.

The initial opening and final closing area normally create an ellipse where flow is concentrated and velocity is high. The Double Arcuate Cut increases that opening by a factor of three (3) and consequently reduces the velocity by actually spreading out the flow. A reduction in velocity will obviously decrease damage. Velocity is reduced both on the upstream and downstream sides.

The Double Arcuate Cut notch provides a blunt, leading edge against flow. The coating is thickest at this point and the elimination of a sharp edge minimizes coating fracture.

 


 

Seats

Standard

  • 410SS/CCC

Optional

  • 17-4PH, 329SS, 316SS, Stellite 6, Inconels, Hastelloys, Monel, Alloy 20, Titanium, Zirconium

Features

  • Sharp leading edges of the seat ring wipe the sealing surface clean each time the valve is operated
  • A wide sealing surface on each seat ring minimizes the possibility of nicks and scratches which cause leakage
  • Each seat is mate-lapped front and back (to ball and body) to ensure the integrity of the seals
  • All metal to metal seals - no Grafoil or Teflon behind the seat

Seat Technology

Mogas uses two different methods of trapping the downstream seat in place. Both methods of locking-in the seat provide sealed seat protection and easy seat removal for repair. By trapping the seat into its proper place, debris cannot get behind the seat and cause leakage.


Coatings

In critical services, the reliability of a valve is often dependent upon proper coating selection. In metal to metal sealing ball valves the ball and seat coating must provide wear and anti-gall properties. Coatings must be compatible with base materials for proper adhesion, corrosion resistance and thermal stability. Mogas has more than 25 years of research and in-service experience that has led to our expertise in coating selection. Once the coating is selected, it is imperative that the coating vendor apply the coating correctly. Mogas approves coating vendors only after extensive metallurgical testing of their coating systems. Selected vendors apply coatings to exact specifications. In addition, random sampling and a vendor audit system ensure that only the highest quality coatings are applied to Mogas valves.

Stem Seal Bearings

Mogas utilizes coated, lapped metal ring/rings between the stem shoulder and the blow out proof pocket in the body. This creates a pressure energized stem seal internal to the valve. The lapped surfaces secure a tight seal that is enhanced by line pressure exerting additional vertical force. This seal saves the stuffing box from thermal shocks and particle migration.The ring/rings also serve as a thrust bearing which eliminate radial movement that can cause packing wear.

Packing Chamber

Mogas utilizes an industry preferred system of two or three sandwiched rings of die-formed Grafoil ribbon between upper and lower braided carbon fiber anti-extrusion rings. This is an optimum system which has enough Grafoil to effect a seal without having redundant rings for show. A heavy stainless steel gland follower, secured by a minimum of four studs, compresses the system. This insures proper load strength and minimizes the possibility of cocking.

Actuator Mounting Flanges

Mogas utilizes a rigidly secured mounting bracket for actuators, wormgears and levers. The bracket, constructed of heavy plate steel, is welded or bolted to the valve body. The mounting plate is parallel to the bore, and perpendicular to the stem, so there is no misalignment of the operator. Mogas places a heavy metal bushing in the bracket of the valve to guide the stem and ensure that the stem does not side load during operation. If side loading occurs, it is absorbed outside the packing chamber and does not deform packing. Deformation of packing caused by side loading is a major cause of stem leakage in rotary valves. All of these components work together to provide the most reliable stem seal in the industry.

Stem Packing

 

Standard Packing

  • Up to 850F - Oxygen Present
  • Up to 1200F - Reducing Atmospheres

Special Features

  • Stainless steel studs and nuts are torqued to meet pressure requirements
  • Heavy duty gland flange
  • Braided carbon fiber anti-extrusion rings surround two to three die-formed Grafoil packing rings
  • Double 410 stainless (typical) rings with chrome carbide coating or single peek filled Teflon make up the inner stem seal bearings

 

Standard Packing with Live Loading

  • Up to 850F - Oxygen Present
  • Up to 1200F - Reducing Atmospheres

Special Features

  • Includes all of the features of the standard stem packing with stainless steel Belleville spring washers and the stainless steel guide spacer

   

 

Dual Stem Packing

  • Up to 850F - Oxygen Present
  • Up to 1200F - Reducing Atmospheres

Special Features

  • Includes all of the features of the standard stem packing
  • Two sets of braided carbon fiber anti-extrusion rings surround two to three die-formed Grafoil packing rings
  • Double 410 stainless (typical) rings with chrome carbide coating or single peek filled Teflon make up the inner stem seal bearings
  • 316 stainless steel molycoated lantern ring situated between the two packing sets

 

High Temperature Packing

  • 850F-1300F - Oxygen Present
  • 850F-1652F - Reducing Atmospheres

Special Features

  • Top - two reinforced composite fiber braided ropes surround two oxygen resistant, corrosion inhibited, die-formed Grafoil packing rings
  • Center - two ceramic fiber gasket insulators and two ceramic fiber braided rope insulators split up to form an oxygen and heat barrier
  • Bottom - Grafoil impregnated, Inconel 718 anti-extrusion and sealing ring, also includes inner stem seal bearings

 

Bolting

The coefficients of thermal expansion of body and bolting materials are important criteria in the selection and design of the bolting on the valve. The bolt sizing criteria is based on generating sufficient load to the seat to retain pressure on the gasket. On both high and low pressure valves, a body bolting make-up torque is specified which provides a preload between the body and end connection. This bolting torque is sufficient to insure there will be no relative movement during pressure or thermal cycling of the valve in service.

Gaskets

  Spiral wound for 150# to 1500# ANSI Class, Inconel with Grafoil for all temperatures

  Pressure energized gold plated delta ring gasket for 2500# to 4500# ANSI Class

  Inconel 718 for Carbon Steel, F-22 & Nickel Alloy body materials

  A638 Gr. 660 for Stainless Steel body material

 

End Connections

Mogas manufactures many valves with almost any style of end connection. All end configurations are machined integral with the body and end connections of the valve, instead of multiple piece construction. The choice of end connection configurations is usually left to the discretion of the customer.