Method of hot tapping a pipe for installing ionic flowmeter transducers

• US 5,396,814 A
• Filed: 05/27/1993
• Issued: 03/14/1995
• Est. Priority Date: 05/27/1993
• Status: Expired due to Fees

• Current Assignee: Mesa Laboratories Inc.
• Original Assignee: Mesa Laboratories Inc.
• Inventors: Ryer, Henry E., Riley, Larry T., Tuttle, Dennis H.
• Primary Examiner(s): NOLAND, THOMAS
• Application Number:
  US08/068,625
• Time in Patent Office: 656 Days
• Field of Search: 73/866.5, 73/861.27, 137/315
• US Class Current: 73/866.5
• CPC Class Codes: F16L 41/04 Tapping pipe walls, i.e. making connections through the walls of pipes while they are carrying fluids; Fittings therefor
• CPC Class Codes: G01F 1/662 Constructional details
• CPC Class Codes: G01F 15/18 Supports or connecting means for meters
• CPC Class Codes: Y10T 137/0402 Cleaning, repairing, or assembling
• CPC Class Codes: Y10T 137/598 With repair, tapping, assembly, or disassembly means
• CPC Class Codes: Y10T 137/6123 With aperture forming means

Abstract

A method of hot tapping a pipe for installing a carrier for use with a sonic flowmeter transducer includes the steps of welding an alignment fixture to the pipe, attaching a drilling device to the alignment fixture, drilling a hole in the pipe, removing the drilling device and replacing it with a cleaning assembly to remove metal shavings, replacing the cleaning assembly with an extraction assembly which is used to remove the drilling device, removing the extraction assembly and installing an insertion assembly to which a carrier is removably attached. The insertion assembly is employed to secure the carrier to the alignment fixture. The insertion assembly and the drilling device are then detached from the alignment fixture and are ready for reuse.

Claims

1. A method of hot tapping a pipe and permanently installing a pair of carriers for use with sonic flowmeter transducers comprising the following steps:

(a) permanently securing first and second alignment fixtures to an outside wall of a pipe so the alignment fixtures are aligned with each other along and parallel to a longitudinal axis of the pipe and are an appropriate distance apart;

(b) removably securing a drill bushing within the first alignment fixture;

(c) removably attaching a hot tapping device equipped with a removably attached drill assembly to an angled surface provided on the first alignment fixture;

(d) opening a valve provided on the hot tapping device and moving a drill bit provided on the drill assembly toward the pipe until the drill bit abuts the pipe;

(e) rotating the drill bit to create a hole in the pipe;

(f) moving the drill bit away from the pipe until the drill bit clears the valve;

(g) closing the valve to isolate the drill assembly from the pipe and opening a pressure relief valve provided on the valve in order to relieve pressure on the drill assembly;

(h) removing the drill assembly from the hot tapping device;

(i) securing a cleaning assembly to the hot tapping device;

(j) opening the valve and moving a magnet provided on the cleaning assembly toward the pipe until the magnet bottoms out in the device and attracts magnetic metal shavings which adhere to the magnet;

(k) moving the magnet away from the pipe until the magnet clears the valve;

(l) closing the valve to isolate the cleaning assembly from the pipe and opening the pressure relief valve in order to relieve pressure on the cleaning assembly;

(m) removing the cleaning assembly from the hot tapping device and cleaning the magnetic metal shavings from the magnet;

(n) repeating steps (i) through (m) until the hot tapping device is cleaned of magnetic metal shavings;

(o) securing an extraction assembly to the hot tapping device;

(p) opening the valve, moving the extraction assembly toward the pipe, engaging the drill bushing with the extraction assembly and removing the drill bushing from the first alignment fixture;

(q) moving the drill bushing away from the pipe until the drill bushing clears the valve;

(r) closing the valve to isolate the extraction assembly from the pipe and opening the pressure relief valve in order to relieve pressure on the extraction assembly;

(s) removing the extraction assembly from the hot tapping device and replacing the extraction assembly with an insertion assembly to which a first carrier is removably attached;

(t) opening the valve, moving the first carrier toward the pipe by means of the insertion assembly and securing the first carrier to the first alignment fixture;

(u) opening the pressure relief valve to check whether the first carrier is properly secured to the first alignment fixture;

(v) removing the hot tapping device from the first alignment fixture; and

(w) repeating steps (b) through (v) for the second alignment fixture and employing a second carrier instead of the first carrier.

2. A method according to claim 1 further comprising the following step:

(x) removably capping the first and second carriers with carrier caps to prevent debris from entering the carriers.