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KR Operation and System Integration Guidelines

1. Flow Capacity:

Consideration must be given to the flow capacity of the interconnect piping between KR Regulators (KR) and the wellhead equipment being operated. Inadequate flow capacity may result in excessive back pressure which can cause the KR to hammer or chatter which is rapid opening and closing as the KR seeks to shutoff at set pressure.

Flow Capacity Table - SCH-80

Nominal

Size

Rated GPM

Outlet

Port

SCH-80
ID
GPM*
PSI
KR-12 (1/8")
2
1/2"
.546
22
4100
KR-38 (3/8")
15
1/2"
.546
22
4100
KR-75 (3/4")
75
1"
.957
67
3500
KR-100 (3/4")
75
1-1/2"
1.5
165
2800
KR-140 (1-1/2")
150
1-1/2"
1.5
165
2800
KR-150 (1-1/2")
190
1-1/2"
1.5
165
2800
KR-200 (2")
300
2"
1.939
276
2500

* @ 30ft/sec


Flow Capacity Table - SCH-160

Nominal

Size

Rated GPM

Outlet

Port

SCH-160
ID
GPM*
PSI
KR-12 (1/8")
2
1/2"
.466
16
7300
KR-38 (3/8")
15
1/2"
.466
16
7300
KR-75 (3/4")
75
1"
.815
49
5700
KR-100 (3/4")
75
1-1/2"
1.338
132
4500
KR-140 (1-1/2")
150
1-1/2"
1.338
132
4500
KR-150 (1-1/2")
190
1-1/2"
1.338
132
4500
KR-200 (2")
300
2"
1.687
209
4600

* @ 30ft/sec

2. Deadband (DB):

  • STATIC DEADBAND is when the KR is at set pressure and a small fluctuation in outlet is caused by a downstream leak, temperature variation or wellbore packer compression. The Static DB is the difference between the lowest outlet pressure before resetting and the pressure that the KR resets to.
  • DYNAMIC DEADBAND is the difference between initial set pressure and the pressure that the KR resets to, after the open flow condition.

3. Set Pressure Adjustment:

When changing (adjusting) the set pressure on a spring operator the outlet needs to be opened and closed briefly a few times to allow the operator and pressure to stabilize. This can be achieved by operating a manifold control valve or installing a separate much smaller valve directly on the outlet line near the KR.

4. Series Installation:

It is NOT recommended to install KR's in series (I.E. do NOT connect the outlet of one KR to the inlet of another). Call our technical support team for the most effective application and installation strategies.

KR Regulator Operation

Regulator at Set Pressure and No Flow:

  • The Operator Force which is acting on the piston is balanced by internal pressure.
  • The Inlet / Supply pressure (red) is blocked and contained by the seal rings in the seal container which are sealing on the flow plates.
  • The internal regulator pressure and the Outlet port / piping are at Set pressure (blue) which is less than the Inlet pressure.
  • The Vent port is connected to the reservoir and is at ambient pressure.
Regulator at Set Pressure and No Flow

Regulator at Full Flow Condition:

  • The Outlet Port / piping which is connected to a hydraulic control valve when actuated causes the internal regulator pressure to drop below the Set pressure.
  • The drop causes the Operator Force to push the piston into the regulator body,
  • the seal rings to change position uncovering the ports on the flow plate,
  • thus causing the Inlet / Supply pressure (red) to flow through the regulator to the Outlet port / piping and in turn the control valve to the equipment function.
  • The Vent port in the flow plate remains covered and sealed by the vent seal ring.
Regulator at Full Flow

Venting to Reservoir:

  • Venting of the regulator is caused either by excessive back pressure on the Outlet port from some other source or by decreasing the Operator Set Force in order to reset the regulator to a reduced pressure.
  • If the regulator internal pressure exceeds the Set pressure it will cause the seal container and piston to move upwards against the Operator Set Force.
  • The Vent seal ring will move off the Vent port in the flow plate and allow the pressure to be vented from the regulator body to the reservoir.
  • The Inlet / Supply port remains sealed.
  • Venting continues until the internal pressure reduces to a point that balances with the Operator Set Force,
  • and the seal container and piston move downward where the Vent seal ring covers and seals off the Vent port in the flow plate.
Venting to Reservoir