Y-pattern globe valves
- Non-rotating stem on y-pattern globe valves
- Fully guided, non-spinning, CoCr alloy disc
- Available in: forged carbon steel, stainless, alloy (including F91
and F92), and nickel alloy steels
- Available with bellows seal
- For nuclear and NACE (sour gas) services
Globe Valve: A globe valve is a type of valve used for regulating
flow in a pipeline, consisting of a movable disk-type element and a
stationary ring seat in a generally spherical body. Globe Valves
are named for their spherical body shape with the two halves of the
body being separated by an internal baffle.This has an opening that
forms a seat onto which a movable plug can be screwed in to close
(or shut) the valve. The plug is also called a disc. In globe
valves, the plug is connected to a stem which is operated by screw
action in manual valves.
Body-Bonnet Connection
The body and bonnet of Class 150 to Class 900 valves are usually
with studs and nuts. And the body and bonnet of Class 1500 to Class
2500 valves are usually of pressure seal design.
Body-Bonnet Gasket
Stainless steel + flexible graphite wounded gasket is used for
Class150 and Class 300 globe valve. Stainless steel + flexible
graphite wounded gasket is used for Class 600, and ring type joint
gasket is optional. Ring joint gasket is used for Class 900 globe
valve. Pressure seal design is used for Class 1500 to Class 2500
globe valve.
Operation
Hand wheel and gearbox operation are applied for globe valve. Chain
wheel and electric is available if required.
Packing Seal
Molded flexible graphite is used for packing material. PTFE or
combined packing material can be applied if required.
The internal surface of the stuffing box, of which area is
contacted with the packing, is of excellent finished (Ra 3.2μm).
The stem surface, contacting with the packing, should be rolled and
pressed after being precisely machined, so as to reach high finish
and compactness (Ra 0.8μm) and ensure the reliable tightness of the
stem area.
Belleville Spring Loaded Packing
If required, Belleville spring loaded packing can be applied to
enhance the durability and reliability of the packing seal.
Back Seat
All our globe valves have the back seating design. In most cases,
the carbon steel globe valve is fitted with a renewable back seat.
For stainless steel globe valve, the back seat is machined directly
in the bonnet or machined after welding. When the globe valve is in
fully open position, the sealing of the back seat can be very
reliable. However, as per the requirement of design standards, it
is not advisable to add or change packing by the mean of back
seating when the valve is under line pressure.
Seat
For carbon steel globe valve, the seat material is usually forged
steel. The sealing surface of the seat is overlay welded with hard
alloy specified by customer. Renewable threaded-in seat is applied
for globe valve NPS≤10, and welded-on seat is optional.
Welded-on seat is used for NPS ≥ 12 carbon steel globe valves. For
stainless steel globe valve, integral seat is usually adopted, or
hard alloy welding directly integrally. Threaded-in or welded on
seat is optional for stainless steel globe valves.
Stem
The stem is of one-piece forged steel. The minimum diameter of the
stem shall be as per the standard requirements.
Stem Nut
Usually, the stem nut is made of copper alloy. It can be made of
ASTM A439 D2 if required. For large sized globe valve, rolling
bearing is fitted at the two sides of stem nut in order to minimize
the open and close torque of the globe valve.
