Your Source for the Highest-Quality Chokes
Installation and Maintenance Instructions
Installation
McDonald Industries Inc. chokes are shipped with the indicator set to 0/64 (closed position). Install choke in system using proper size mating flanges or threaded end connections and appropriate gasket seal rings or thread sealant. The indicator setting may be relocated for more convenient reading by loosening wing nut and rotating bonnet as desired.
Caution: Choke must be in open position and internal system pressure must be bled to 0 PSI prior to making this adjustment. Retighten wing nut. Turn hand wheel clockwise until choke is in closed position (0/64). With choke closed, turn indicator until 0/64 is positioned directly above the indicator reading notch. Indicator set screw will now be accessible through round window in side of bonnet. Tighten set screw. Indicator is now set.
Operation
As the choke is opened, numbers will appear in the indicator-reading notch, indicating the equivalent orifice setting of the choke, in 64th of an inch. Once the choke has been set at the desired orifice size, thumbscrew should be tightened to secure that setting. Flow may now be opened through the choke. Should further adjustment be necessary, simply loosen the thumbscrew, turn the hand wheel in the direction needed to correct the flow, then re-tighten thumbscrew.
Maintenance
Routine maintenance on McDonald Industries Inc. chokes consists of periodic injection (once a month is adequate) of lithium grease through the grease fitting. In the event major service or rebuild is required, the stem, seat, stem packing and bonnet seal may be replaced without removing the choke body from the piping system.
Caution: If the choke is to be disassembled while installed in a piping system, it must be isolated from the system pressure and flow. With the choke at an open setting, internal pressure must be bled to 0 PSI.
1 13/16” and 2 1/16” Flanged and Threaded
API 5,000psi and 10,00 psi CWP Adjustable and Positive Chokes
Disassembly
Loosen nut and set screw. Then, remove hand wheel, indicator, and thumbscrew and thread lock protector. Loosen wing nut with hammer blows (turn counter-clockwise looking into the handle-end of stem) and remove wing nut and bonnet, stem, and packing as an assembly (we call it a bonnet assembly).
To disassemble the stem from this assembly, screw the bonnet off the stem’s square end. When the threads become disengaged, pull the stem and bonnet apart. Remove stem packing retainer from the bonnet and pry out the steel junk ring and packing rings with a screwdriver (be careful not to damage stuffing box bore in bonnet).
Finally, remove seat from the body using a common choke wrench (M23CWXX). Clean and inspect bonnet seal and all other components for wear and corrosion. Discard and replace all questionable parts.
Reassembly
Assemble the stem/bonnet/packing sub-assembly by placing the seal rings (lips toward point of stem) and the steel packing junk ring on the stem. Note: 1” orifice chokes require that the packing and junk ring be installed from the threaded end of the stem. Use of grease on the stem will facilitate moving these parts over the threads to their proper location, just behind the point of the stem. Take care that the packing is installed with the junk ring closest to the point of the stem followed by the seal rings. Screw the bonnet and stem together and seat the packing/junk ring in the stuffing box, exposing the retainer ring in groove. Reassemble other components in reverse order of assembly. After assembly is complete, inject several pumps of lithium grease through grease fitting, and re-calibrate indicator per the Installation and Operations Instructions.
Shipping
Adjustable chokes should be shipped with the stem in the partially open position.
Warranty Details/Terms and Conditions
McDonald Industries Inc. warranties products of our manufacture one year from date of shipment to the extent that McDonald Industries Inc. will replace any products of defective workmanship proven under normal use and service. No other warranty is expressed or implied. We specifically are not responsible for damages or injury, direct or indirect, or for damages or failures caused by improper installation, operation or misuse.
Goods or parts thereof, not manufactured by us, are guaranteed only in accordance with the manufacturer’s guarantee and only to the extent that we are able to enforce it.
All claims for in-transit shortages, damages or erroneous charges must be made within thirty (30) days from receipt of shipment and must be accompanied by the packing list(s) covering shipment.
McDonald Industries Inc. strives to pack and prepare all shipments so that they will not break, rust or deteriorate in transit but do not guarantee against such damage.
McDonald Industries Inc. reserves the right to change or modify the design and/or construction of any McDonald Industries Inc. product in due course of manufacturing procedure without notice and without incurring any obligation to furnish or install such changes or modifications on products previously or subsequently sold. Any other representation, warranties or conditions, expressed or implied, relating to materials, equipment or services provided by McDonald Industries Inc. are excluded, unless specifically agreed in writing by McDonald Industries Inc.
All sales made by McDonald Industries Inc., unless otherwise agreed to in writing by the executive officer of the company, are made subject to each and all of the foregoing conditions and the placing of an order or the acceptance by the customer of the above said conditions.
All Requests Should Be Mailed or Emailed To:
Phone: (318) 226-1339
Fax: (318) 425-8029
[email protected]
McDonald Industries Inc.
451 Fortson Street
Shreveport, LA. 71107
New, unused products of our current manufacture may be returned for credit, provided a written request is received within (12) months after purchase date. Special or discontinued and/or obsolete products are not returnable for credit. Restocking charges may apply and will be determined at request.
Material returned for credit shall be shipped via prepaid freight, to our specified destination. The credit allowed on returned goods is a merchandise credit and applicable only against purchase of our products. Credit will be allowed under the original price, or at a subsequently adjusted price.