FREQUENTLY ASKED QUESTIONS

Survey Questions

HOW DOES LDS TEST FOR LEAKS?

We use the LDS patented ValveAlyzer^®; System, site specific databases, custom test procedures, acoustic testing, complex thermal analysis, and other proprietary data analysis methods, to identify leaking Cycle Isolation Valves and Traps.

A SURVEY:
Tests all economically repairable cycle isolation valves.
Is completed prior to a scheduled outage.
Produces a complete list of valves that are economic to repair.
Identifies approximately 10 high-priority valves to fix.

HOW MANY VALVES PER DAY ARE TESTED?

HOW MANY PEOPLE DOES LDS SEND?

We normally send 2 LDS personnel. Occasionally we will send one for various reasons, such as job scope, availability, etc.

WHAT SUPPORT DOES THE PLANT HAVE TO PROVIDE?

1. We will need your P&IDs
   - (Flow Diagrams) and Heat Balance Diagram
   - (Full Power) for the database
   - and Loss Potential Analysis
2. A contact person is required to answer questions about the diagrams
3. Insulators may be required to install inspection holes. See below for more details on hole preparation.
4. 1 and sometimes 2 Operators are needed to locate and stroke valves during testing.
5. An Instrument Tech should be on call to adjust controls and actuators as needed.
6. Prior to Post-Outage testing, LDS will need a list of fixed valves and related details.

WHAT IS REQUIRED
FOR PROPER INSPECTION HOLE PREPARATION?

Prior to our arrival on-site, you will receive a detailed valve list of each item flagged for testing, including any associated isolation valves. It is always recommended that inspection holes be prepared before we arrive and in accordance with the valve list.
The following provides a general guideline for the creation of inspections holes.

A) Our preferred tests call for the normally closed valve to be tested with and without the differential pressure. This requires the isolation valves to be manipulated. Every valve to be tested, including isolation valves, will need an access point for testing.

We need access directly to the valve body/outlet piping, as close to the downstream side of the valve seat as possible.
Avoid weld beads because their roughness makes transducer contact poor.
If the insulation is a cloth blanket that can be peeled back, a hole is not necessary.
We require an 2” insulation port, made with a common hole-saw bit on a portable drill.
If asbestos is present, a qualified asbestos worker is necessary to create the port(s).

B) If the differential pressure cannot be removed, or the isolation valve(s) are already closed, we will also need two additional access points (per closed valve to be tested)

We will need one hole upstream, and one hole downstream of the closed valve.
These holes should be at least 10 pipe diameters away from the valve to be tested.
If an open isolation valve is at least 10 pipe diameters away, the access point on this isolation valve (insulation hole, blanket removal, etc) is sufficient.
If it is not safe (or impossible) to access a point farther than 10 pipe diameters away, have the holes drilled as far away as possible from the closed valve

WHEN SHOULD A SURVEY BE COMPLETED?

A Pre-Outage Survey should be completed to provide ample time for parts ordering etc. You will receive your final report within 10 days of on-site test completion. Fossil stations typically require 4-6 month lead time to ensure parts availability. Nuclear plants typically require 6- month lead time to ensure parts availability.

HOW OFTEN
SHOULD A PRE-OUTAGE SURVEY BE COMPLETED?

A Pre-Outage Survey should be completed prior to all scheduled outage starts (short or long).
Surveys should be completed annually and at least 2 months before any scheduled short/rediness outage. This will maintain a current short list of valves to work in case of a short outage – planned or forced.

HOW OFTEN SHOULD A POST-OUTAGE SURVEY BE COMPLETED?

Post-Outage Surveys should be completed within two months or repairs and outage completion.

WHY COMPLETE POST-OUTAGE TESTING?

LDS encourages its clients to conduct post-outage testing to confirm repair success and to identify any potential new problems. A post-outage report identifies estimates of your plant’s cycle isolation loss improvement as a direct result of your efforts.

HOW MUCH DOES A SURVEY COST?

We provide a significant return on investment with a very short payback period. Typically, a survey costs 5 times less than a plant’s overall savings. Our services are provided on a flat-fee, all-inclusive pricing method that includes both Pre and Post Outage testing. Pricing varies based on plant type and client status.
Please contact a sales representative at 800.345.7157 to receive a formal no-obligation quote and cost/benefit analysis.

WHAT WILL BE IN THE REPORT?

The report includes a list of leakers, in economic order for repair. Estimated fuel cost recovery is listed for each leaker. There is also a list of tight valves that can be used to clear unnecessary work orders.
Where appropriate, LDS may also make specific repair recommendations.

HOW SOON CAN WE GET THE REPORT?