JST Seals can provide vee packing manufactured from its range of high performance elastomers, PTFE and PEEK. Typical applications include mud pump packing, where the seal encounters high pressure and grinding media containing various solids, oil and water.

The objective of this test procedure is to evaluate the quality of  JST non elastic seal, V-Packing seal stack design as per API 19LH for bi-directional zero bubble performance at gas pressure of 10,000 PSI and at max temperature of 350 ℉ with temperature cycle of 140℉, post five mechanical “stabbings” at 280 ℉. The test procedure is refer to V1 testing of V-Packing 7.375inch OD which provided by JST. The test condition & requirement are shown as follow:

Temperatuer: 98.9℃~176.7℃ (210℉~350℉)

Pressure: 10000psi

Bleeding pressure: ≤200psi/min

Media: Nitrogen gas & Hydraulic fluid（Transaqua™ HT2）

Test specimen: V-PACKING 6.750 ID X 7.375 OD

VZQ1715ZY3G02

Fixture:#103640289

2. Drawing and Test Fixture Assemblies

3. Testing Steps

1. While heating the fixture, make sure to stabilize the temperature by allowing appropriate soaking time (approx.~2 hrs) to allow uniform heating.

2. Before each pressure hold, make sure pressure stabilizes before starting the hold duration

3. Pressure stabilization: allowing the pressure to get settled to a target value before starting of hold period

4. For bubble test: connect one end of tube/line to bubble detection port and other end inside a glass of water to observe the gas leaks

5. Gradually increasing the pressure to set pressure during hydraulic test @ step of 3000 psi and hold for 1 min at each step

6. Unless otherwise specified by supplier/manufacturer, hydraulic pressure-relieving (bleed-down) operations shall be performed at a rate of 6.9 MPa bar (1000 psi) per minute

7. Gradually increasing the pressure to set pressure during gas test @ step of 1500 psi and hold for 1 min at each step

8. Bleed the gas pressure at ~ 200 PSI/min.

9. Applied pressure across seals is differential pressure. Never exceed the absolute pressure on one side above 12000psi.

10. Please make sure that the Nitrogen is bled at well ventilated area to avoid safety issues to personal around

11. Check the calibration due date for measuring and monitoring equipment used during the testing

12. Five mechanical stab includes (stab-in, stab-out, stab-in, stab-out, stab-in).

13. Do not exceed the stabbing pressure more than 1000psi.

14. Housing (13), seal sub (14) pre-test dimensional inspection should minimum includes all dimensions with tolerance less than 0.005in, inspect sealing surfaces which have Ra 63 or less

15. Conduct the full dimensional inspection for V-packing (1).

16. Record the temperature and pressure during the test.

17. During test collect all video or pictorial evidence.

18. LVDT or String Potentiometer must be used to measure piston movement

19. During test if any of the objective for a given step is not met. Please contact engineering before proceeding

4. Acceptance Criteria

The Acceptance criteria refers to API 19LH V1: No bubbles can leak into the hydraulic chambers in 15mins.

5. Seal Stack Inspection & Assembly

Figure 8-1: Dimensional inspection of Seal stacks pre/post-test

Visual Inspection of Seal Stack

The test result shows that after post five mechanical “stabbings” at 280 ℉:

1. No bubble was observed at 350℉ gas test in 15min

2. No bubble was observed at 210℉ gas test in 15min

The test result meets the acceptance criteria, JST V- packing Seal Stack pass the test successfully.