Cast Steel Gate Valve

BODY & BONNET

The design of the body and bonnet is calculated to achieve the most regular distribution of stress in all directions, as well as the minimum turbulence and resistance to flow. Valve bonnets are equipped with a backseat bushing. The yoke is integrally cast on Pressure Classes 150 and 300 up to 12” and up to 10” on Class 600 and higher ratings.

BODY-BONNET JOINT
Standard body-bonnet joints of gate valves are machined
as follows:
PRESSURE CLASS JOINT DESIGN
150 Flat Faced
300, 600 Male-and-Female
900* & over Ring Type Joint
*Pressure Class 600 also available in Ring Type Joint.
EMFLO  can supply any style of gasket required by customer.

GATE

All gates are fully guided to the seats. As standard our valves are supplied with a solid flexible gate that has a tapered H cross-section. The flexible wedge is cast or machined with a circumferential groove to allow the seating surfaces to move independently and adjust to movement of the body seats. This design is beneficial where line loads or thermal expansion of the system is likely to distort the seat face in the valve. This design of gate is ideally suited for steam or other high temperature services and is especially useful to prevent sticking where valves are closed when hot and opened when cold.

SEAT RING

Seat rings are designed to greatly reduce and/or prevent any turbulence and avoid damages due to the corrosion. The seat rings are forged or rolled in one piece, and then seal welded and overlaid, if required. After welding and all required heat treating, the seat ring faces are machined, thoroughly cleaned and inspected before leaving for assembly.

STEM

The stem connection to the gate is a T-head design which is integral (without welding) with the stem. The accuracy in the dimensions and finishes assure a long life with a perfect tightness in the packing area, resulting in lower fugitive emissions. The stem-to-gate connection is designed to prevent the turning or the disengagement of stem from the wedge while the valve is in service. Through calculations and extreme testing, the strength of the stem-to-gate connection has proven to exceed the strength of the stem at the root of its operating thread.

STEM PACKING

The stem packing is designed and arranged to ensure a maximum seal along the stem during operation or while at position, thus allowing for a greater reduction in fugitive emissions. Our packings are NON-ASBESTOS types. EMFLO can supply any style of packing required by our customer.

STUFFING BOX

The depth of the stuffing box allows for a sufficient amount of packing, which makes the stem seal. Our standard packing arrangement and stuffing box design meets