US 4,470,280 A · Swaging apparatus with timed pre-fill

Abstract

In an apparatus for forming leak-proof joints between tubes and a tube sheet by the internal application of hydraulic swaging pressure, the flow of relatively low pressure fluid from a pressure source to an intensifier is permitted or interrupted by a control valve. During a prefill period, a prefill valve causes the low pressure fluid to bypass the low pressure input side of the intensifier and flow directly to the high pressure side and then to a mandrel. Thereafter, the low pressure fluid is caused to enter the low pressure side of the intensifier to increase the pressure in the mandrel during a swaging period. A pressurization sensor, which is connected to the input and output sides of the prefill valve, contains a piston which is movable in response to the difference in the pressures at these two points to produce a termination signal which, after a delay, actuates the control signal at the end of the swaging period.

Claims12

Dependent claims

An apparatus for forming leak-proof joints between tubes and tube sheets by the application of hydraulic swaging pressure comprising:

pressure source means for supplying a hydraulic fluid under relatively low pressure;
mandrel means including associated conduits for delivering said pressurized hydraulic fluid to said tubes internally;
intensifier means for increasing the pressure of said fluid, said intensifier means having a low pressure input side and a high pressure output side connected to said mandrel means;
and
prefill means for causing said low pressure fluid to flow first to said mandrel during a prefill period, thereby prefilling said mandrel and said tube, and thereafter causing said low pressure fluid to flow to said input side of said intensifier to commence a swaging period, said prefill means including timer means for measuring a predetermined prefill period.

2 more elements

An apparatus for forming leak-proof joints between tubes and tube sheets by the application of hydraulic swaging pressure comprising:

pressure source means for supplying a hydraulic fluid under low pressure;
intensifier means for increasing the pressure of said fluid to a relatively high pressure suitable for swaging said intensifier means having a low pressure input side and a high pressure input side, said output being connected to said pressure source means to receive said low pressure fluid directly therefrom;
mandrel means adapted to be inserted in said tubes for delivering said fluid to said tubes internally at said high pressure;
and
prefill valve means through which said pressure source means is connected to said input side of said intensifier means, said prefill valve means having a first condition in the flow of low pressure fluid to said input side is blocked during a prefill period to permit side mandrel to be prefilled at low pressure through said output side, and a second condition in which the flow of said low pressure fluid to said input side is permitted during a swaging period, thereby causing said intensifier means to provide high pressure fluid to said mandrel at high pressure after said mandrel and tube have been prefilled at said low pressure.

2 more elements

Dependencies are inferred from the claim text.

Swaging apparatus with timed pre-fill

Life of this patent

Swaging apparatus with timed pre-fill

Life of this patent

Abstract

Claims12