Emerson Yarway b Manual

YARWAY SEATLESS BLOW-OFF VALVES

Type b and Type c

Installation, operation and maintenance instructions

PRINCIPLE OF OPERATION

The seatles blow-off valve is a manually

operated sliding primarily for boiler blow-off

service where high temperature fluid,

containing dirt, sediment and scale, is

encountered.

When the valve is open (Fig. 2) the controlled

fluid passes through the ports in the plunger

(8) and lower gland (5) and discharges to the

valve outlet via the center of the plunger

assembly. In the closed position the shoulder

of the plunger assembly contacts the upper

gland (6). This feature provides additional

loading from the handwheel to compress the

packing rings (3) (4) and assure leak-tight

shut-off. Any packing relaxation during service

is accommodated by the heavy compression

springs (14) which provide a constant packing

load.

VALVE OPERATION

Open the valve quickly and fully. Never use this

valve to throttle the flow in the partly open

condition as this will reduce the packing life.

Close the valve in the same manner. Apply a

hard turn at the end of the valve travel. This

will assure that the plunger seats against the

upper gland which, in turn, will recompress

the packing rings.

In operating Yarway seatless valves in tandem,

the valve next to the boiler should be used as

the blowing valve, opened last and closed first.

The outside or sealing valve should be opened

first and closed last.

If a Yarway double tghtening valve is used in

tandem with a Yarway seatless valve, the

double tighteningvalve is placed next to the

boiler and is opened first and closed last. The

Seatless or outside valve is the blowing valve

and is opened last and closed first.

WARNING

Hot discharge from this product may cause severe

burns. Discharge must be piped away or directed

so that persons in the vicinity are not endangered.

This product must be isolated, vented and cool to

the touch before repairing or inspecting.

10,10A

15A

YARWAY SEATLESS BLOW-OFF VALVES

Type b and Type c

MAINTENANCE AND ADJUSTMENT

Packing ring adjusment

Yoke nuts (15A) should be tightened at regular

intervals. The yoke springs (14) will maintain a

constant load on the packing. Packing rings

will relax slightly during use and an adjustment

may be required. To adjust the packing,

back the plunger off slightly by turning the

handwheel (do not allow flow to occur) and then

tighten the yoke nuts. Approximately ¼ to ½

turn should be sufficient. Reseat the plunger

against the upper gland.

NOTE:

If the valve has not been operated for a long period, the

packing nuts should be adjusted prior to blowing down

the boiler.

Lubrication

A fitting (2A) is provided on the yoke for

lubricating the ball thrust bearing (11) and the

stem collar. This fitting is compatible with an

Alemite No. 7585 gun. A high temperature

grease equivalent to Texaco Regal AFB2

should be used to lubricate this area. Stem

threads should be kept well lubricated. A good

grade of antiseize compound similar to Never-

Seez NS165 should be used. Both of these

areas should be lubricated every six months.

Installation of packing rings

WARNING

This procedure should not be attempted unless all

pressure has been vented from the valve, and its

connecting lines, and the temperature of the valve

is at or near ambient.

Remove the stopscrew (10) then remove the

yoke nuts and springs. Turn the handwheel to

open the valve. This will raise the plunger. Turn

the handwheel to close the valve. This will raise

the yoke. Turn the yoke so that the holes and

studs are out of line and turn the handwheel to

open the valve. The plunger is thus withdrawn

from the valve.

Next, remove the glands and the old packing.

This can be done by using a Yarway gland and

packing puller or similar tool (Fig. 3) in the

following manner: Insert the tool until the

pawls engage the ports in the lower gland.

Tighten the nut on the top of the puller to draw

out the lower gland, upper packing and upper

gland. The lower packing can then be removed

using a hook tool. Care should be exercised,

however, so that the lower packing groove is

not damaged. Install new packing rings, (Fig. 4

or 5) glands and stopscrew in the body and

replace the yoke, with the plunger screwed all

the way up on the stem, in place and using the

yoke nuts pull down the yoke assembly. Next,

place the springs under the nuts and adjust as

previously described.

TYPE C ANGLE VALVE

Item Description

FIGURE 2

Type C angle valve

NOTE:

When ordering parts, use parts numbers and names

shown in table, specify size and type of valve, figure

number and operating pressure (see nameplate on

valve). Maintenance kits for Type B valves include

the following: cast iron valve, 250 psi: upper & lower

glands, packing set, springs, studs, nuts, stop screw,

stop screw gasket, cast steel valve, 300 psi & 400

psi: upper and lower glands, packing set, stem, ball

bearing, springs, studs, nuts, stop screw gasket.

1Body

2Yoke

2A Lubrication fitting

3Lower packing ring assembly

4Upper packing ring assembly

5Lower gland

6Upper gland

8Plunger assembly

9Stem

9A Stem nut

10 Stop screw

10A Stop screw gasket

11 Rail thrust bearing (2 Type C; 1 Type B)

12 Handwheel

13 Extension lever (Type C only)

14 Yoke springs (4 per set)

15 Yoke studs (4 per set)

15A Yoke stud nuts (4 per set)

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RIGHT TO KNOW LAWS AND OSHA STANDARD

29CFR (1910.1200)

Material Safety Data Sheets on the following

Yarway products: Valves, Steam Traps and

Strainers

The OSHA Hazard Communication Standard

29CFR 1910.1200, states that the standard does

not apply to “articles.” The standard defines an

article as:

“A manufactured item formed to a specific

shape or design for a particular use which does

not release or otherwise expose an employee to

a hazardous chemical under normal conditions

of use.”

The above named products fall within the

definition of an “article”, no Material Safety

Data Sheets are available or are required. Our

product is manufactured as an “end product.”

If the product is a weld end the following

applies.

YARWAY SEATLESS BLOW-OFF VALVES

Type b and Type c

NOTE:

Any malfunction of this product must be reported to

the service department. Repair made to the product by

unauthorized personnel will void the warranty.

WARNING

Materials used in manufacture of Yarway

products are considered in a stable condition

when shipped. However, under certain conditions

purchasers could create potential hazardous

conditions by their future operations.

CAUTION

Welding, cutting, burning, machining or grinding

of this product can generate toxic dust and fumes

of potentially hazardous ingredients. The dust

or fumes can cause irritation of the respiratory

tract, nose, throat, skin and eyes. It may cause

temporary or permanent respiratory disease in

a small percentage of exposed individuals. Use

moderate ventilation when grinding or welding.

Avoid breathing dust, fumes or mist. Avoid

prolonged skin contact with dust or mist. Maintain

dust levels below OSHA and ACGIH levels. Use

protective devices. Wash hands thoroughly after

contact with dust before eating or smoking.

FIGURE 4

Without support ring

FIGURE 5

With support ring

FIGURE 3

Seatless blow-off valve gland and packing

assembly

PARTS LIST

Item Description

GLAND AND PACKING PULLER

Item Description

1Bridge plate assembly

2Jack screw

3Spring

4Thrust washer

5Nut 1¼” hex

6Screw (spring mtg.)

946458 Packing puller w/box*

946459-01 1”, 1¼” Head assembly

946459-02 1½” Head assembly

946459-03 2” Head assembly

946459-04 2½” Head assembly

Upper gland

Upper packing

backup ring

Upper packing ring

Valve inlet

Plunger

Lower gland

Support ring

Lower packing ring

Upper gland

Upper packing

backup ring

Upper packing ring

Valve inlet

Plunger

Lower gland

Lower packing ring

Valve body

Upper gland

Lower gland

Upper packing

Lower packing

Note: chisel

marks on head

give indication

of direction of

pawls when

inside valve body

Edge of hole peened

to hold pin in place

Head assembly interchange head assembly available

for either 1”, 1¼”, 1½”, 2” or 2½”valves. order size or

sizes required.

Head assembly fits all types of Yarway seatless

valves in size specified

Neither Emerson, Emerson Automation Solutions, nor any of their affiliated entities assumes responsibility for the selection, use or maintenance of any product.

Responsibility for proper selection, use, and maintenance of any product remains solely with the purchaser and end user.

Yarway is a mark owned by one of the companies in the Emerson Automation Solutions business unit of Emerson Electric Co. Emerson Automation Solutions, Emerson

and the Emerson logo are trademarks and service marks of Emerson Electric Co. All other marks are the property of their respective owners.

The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not to be

construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. All sales are governed by

our terms and conditions, which are available upon request. We reserve the right to modify or improve the designs or specifications of such products at any time without

notice.

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